A Study of Lean Construction Practices in Gaza Strip

The Islamic University of Gaza
Deanery of Higher Studies
Faculty of Engineering
Civil Engineering Department
Construction Management
A Study of Lean Construction
Practices in Gaza Strip
ةﺰﻏ عﺎﻄﻗ ﻲﻓ
ﺲﻠﺴﻟا ءﺎﻨﺒﻟا
ﻖﻴﺒﻄﺗ
Ramdane M. El-Kourd
Supervised by
Dr. Salah R. Agha
Dr. Mamoun A. Alqedra
ةﺰﻏ - ﺔﻴﻣﻼﺳﻹا ﺔﻌﻣﺎﺠﻟا
ﺎﻴﻠﻌﻟا تﺎﺳارﺪﻟا ةدﺎﻤﻋ
ﺔﺳﺪﻨﻬﻟا ﺔﻴﻠآ
ﺔﻴﻧﺪﻤﻟا ﺔﺳﺪﻨﻬﻟا ﻢﺴﻗ
ﻊﻳرﺎﺸﻤﻟا ةرادإ
ﺔﺳارد
A Thesis Submitted in Partial Fulfillment of the Requirements for the
Degree of Master of Science in Construction Management
July, 2009

Dedication
I would like to dedicate this work to my family for
their sacrifice and endless support
Ramdane Mohammed El-Kourd
I

Acknowledgment
I would like to express my deepest appreciation to my
supervisors Dr. Salah R. Agha and Dr. Mamoun A.
Alqedra for their professional guidance, useful advice,
continuous encouragement, and support that made this
thesis possible.
Deepest thanks go for the staff of construction
management at the Islamic University for their
academic and scientific supervision during my study at
the Islamic University.
Gratitude is due to Abu-Shahla consultant office for
their help in providing the required documents.
II

III

ABSTRACT
This research deals with the problem of waste in time, materials, resources and
achievement of customer needs. This study has been applied to a contracting company
in the construction of a project located in GAZA. The main objective of this study is to
apply the principles of lean to the construction in the Gaza Strip. The mechanism of
research implementation consists of two stages:
Stage one: Theoretical study of various Arabic and English references and Master
researches from the Islamic University, studies that deal with the waste and the problem
of contractors’ performance. The criteria that have been derived can be applied to
construction projects in the Gaza Strip.
Stage two: The methodology of applying lean construction was represented in 10
points, the standardization tools and the five why tools as described in the current study
in order to achieve the lean construction in reducing the activity and steps, thus
minimizing the duration by the elimination of the non-value added process in the
activity by using arena simulation.
The study of the project has been implemented in the Gaza strip because of the lack of
projects under construction due to the situation in the Gaza Strip. The data of the
project was taken from the daily reports. These reports showed the duration and steps of
the process for executing the project. Measuring the value and the non-value added in
the process that used standardization tools and showed the cause of waste by using the
five why tools. Consequently, defining solution to deal with them.
Using simulation was to measure the effect of non-value added on each process in the
project.
Results showed that using lean construction reduced the number of steps in the whole
project by 57%. The non-value added decreased from 81% to 14% in the duration of the
project. The total cycle time of the project was reduced by 75%.
Lean construction is new in the field of construction in the world in general and in the
Arab countries in particular.
After proving the potential of applying lean, the focus should be on obstacles of lean
implementation.
IV

Table of Contents
Dedication.........................................................................................................................I
Acknowledgment.............................................................................................................II
Arabic Abstract............................................................................................................. III
Abstract.......................................................................................................................... IV
Table of Contents........................................................................................................... V
List of Abbreviations ................................................................................................. VIII
List of Tables ................................................................................................................. IX
List of Figures............................................................................................................... .XI
Chapter One: Introduction
1. 1 Statement of the problem............................................................................ 2
1. 2 Research aim and objectives....................................................................... 2
1.3 Methodology outline................................................................................... 2
1.4 Thesis contents............................................................................................ 2
Chapter Two: Lean Construction
2.1 The history of Lean Construction ................................................................... 4
2.2 Lean Construction Definition ......................................................................... 5
2.3 Impact of Lean Construction .......................................................................... 6
2.4 Lean Construction Principles...........................................................................6
2.4.1 Value ........................................................... 6
2.4.2 Value Stream ........................................................... 6
2.4.3 Flow ........................................................... 7
2.4.4 Pull ........................................................... 7
2.4.5 Perfection ........................................................... 7
2.5 Criteria of Lean construction ......................................................................... 9
2.5.1 Non Value-Added Activities Reduction.......................................... 9
2.5.2 Increase Output Value ................................................................... 9
2.5.3 Variability Reduction....................................................................... 9
2.5.4 Cycle Time Reduction ................................................................... 10
2.5.5 Simplify by Minimizing the Number of Steps............................... 11
V

2.5.6 Increase Output Flexibility ............................................................ 12
2.5.7 Increase Process Transparency ...................................................... 12
2.5.8 Focus Control on the Complete Process........................................ 13
2.5.9 Build Continuous Improvement into the Process .......................... 13
2.5.10 Balance Flow Improvement with Conversion Improvement....... 14
2.5.11 Benchmark................................................................................... 14
2.6. Tools of Lean Construction
2.6.1 Just in Time (JIT).......................................................................... 15
2.6.2 Last Planner System....................................................................... 16
2.6.3. Increased Visualization................................................................. 18
2.6.4. First Run Studies........................................................................... 19
2.6.5. Daily Huddle Meetings................................................................. 19
2.6.6. The 5s Process .............................................................................. 20
2.6.7. Fail-Safe for Quality ..................................................................... 21
2.6.8 Productivity Standardization.......................................................... 21
2.6.9 The Five Why's ............................................................................... 22
2.7 Construction Waste..................................................................................... 22
2.8 Construction Waste in Gaza Strip............................................................... 25
2.9 Summary ..................................................................................................... 29
Chapter Three: Methodology
3.1 Research Strategy ........................................................................................ 31
3.2 Data Collection ............................................................................................. 31
3.3 Application of Lean Principles in Construction ........................................... 33
Chapter four: Application
4.1 Project Description ....................................................................................... 35
4.2 Project Activities........................................................................................... 36
4.3 Lean criteria Procedure................................................................................. 36
4. 4 Non Value Added Process Identification..................................................... 41
4 .4.1 Mobilization and Excavation Activity............................................. 42
4.4.2 Plain Concrete................................................................................... 42
4.4.3 Foundation Activity.......................................................................... 43
4.4.4 Neck Column Activity...................................................................... 44
VI

4.4.5 Isolation ............................................................................................ 45
4.4.6 Backfilling ........................................................................................ 45
4.4.7 Ground Beam ................................................................................... 46
4.4. 8 Ground Floor Column ..................................................................... 46
4.4. 9 Ground Floor ................................................................................... 47
4.4.10 Ground Floor Slab ......................................................................... 48
4.4.11 First Floor Columns........................................................................ 48
4.4.12 First Floor Slab ............................................................................... 49
4.4.13 Ground Floor Building.................................................................... 50
4.4.14 First Floor Building ........................................................................ 51
4.5 Remove or Reduce the Influence of Waste .................................................. 52
4.5.1 Mobilization and Excavation Activity................................................. 59
4.5.2 Plain Concrete...................................................................................... 59
4.5.3 Foundation ........................................................................................... 60
4.5.4 Neck Column ....................................................................................... 60
4.5.5 Isolation ............................................................................................... 61
4.5.6 Backfilling ........................................................................................... 61
4.5.7 Ground Beam....................................................................................... 62
4.5.8 Column Ground Floor.......................................................................... 62
4.5.9 Ground Floor........................................................................................ 63
4.5.10 Ground Floor Slab ............................................................................. 63
4.5.11 Column First Floor............................................................................. 64
4.5.12 First Floor Slab .................................................................................. 64
4.5.13 Building in Ground Floor .................................................................. 65
4.5.14 Building in First Floor ....................................................................... 66
4.6 Identify the Cause of Wastes ........................................................................ 66
4.7 Finding the Largest Non-Value Added Activity........................................... 69
4.7 Application of Lean Construction for Future Construction Project ............. 79
Chapter Five: Conclusions and Recommendations
5.1 Conclusions................................................................................................... 82
5.2 Recommendations…..................................................................................... 83
References...................................................................................................................... 84
VII

Appendices
Appendix (A): Daily Report
Appendix (B): Arena Simulation
Appendix ( C): Simulation result of the project before applying eight points and after
applying lean tools
Appendix (D): Simulation Result after applying "0" for three biggest non-value added
processes of the project during applying eight points
VIII

F. Floor First Floor
G. Floor Ground Floor
List of Abbreviations
IGLC International Group of Lean Construction
JIT Just in Time
LC Lean Construction
LPS Last Planner System
NUMMI New United Motor Manufacturing Inc.
NVA Non Value Added
PMI Project Management Institute
PPC Percent Plan Complete
RPS Reverse Phase Scheduling
PS Pilot Study
SN Steps Number
SWLA Six-Week Look Ahead
TMS Toyota Manufacturing System
VA Value Added
VAS Value Added Steps
VSM Value Stream Mapping
IX

List of Tables
Table 2.1: Conceptualization of lean principle in construction........................................ 8
Table 2.2: 5S Purpose and Goals.................................................................................... 20
Table 3.1: Productivity of resources in Gaza Strip……………………………………..32
Table 4.1: Details of project .......................................................................................... 35
Table 4.2: Productivity of the Project activities ............................................................. 38
Table4.3: NVA and VA activities in mobilization and excavation ................................ 42
Table 4.4: NVA and VA processes in plain concrete ................................................... 42
Table 4.5: NVA and VA processes in foundation ........................................................ 43
Table 4.6: NVA and VA processes in neck column ....................................................... 44
Table 4.7: NVA and VA processes in isolation.............................................................. 45
Table 4.8: NVA and VA processes in Back filling......................................................... 45
Table 4.9: NVA and VA processes for ground beam activity........................................ 46
Table 4.10: NVA and VA processes for G.Floor column .............................................. 46
Table 4.11: NVA and VA processes for ground floor.................................................... 47
Table 4.12: NVA and VA processes in slab for Ground Floor....................................... 48
Table 4.13: NVA and VA processes in column for F.Floor........................................... 49
Table 4.14: NVA and VA processes in slab for first Floor ............................................ 49
Table 4.15: NVA and VA processes in building for G.Floor......................................... 50
Table 4.16: NVA and VA processes in building for F.Floor.......................................... 51
Table 4.17: Simulation result.......................................................................................... 56
Table 4.18: Waste elimination in mobilization and excavation...................................... 59
Table 4.19: Waste elimination in plain concrete ............................................................ 59
Table 4.20: Waste elimination in Foundation................................................................. 60
Table 4.21: Waste elimination in column neck .............................................................. 60
Table 4.22: Waste elimination in isolation ..................................................................... 61
Table 4.23: Waste elimination for backfilling............................................................... .61
Table 4.24: Waste elimination in ground beam.............................................................. 62
Table 4.25: Waste elimination for ground floor column .............................................. .62
Table 4.26: Waste elimination for ground floor ............................................................ .63
Table 4.27: Waste elimination for G.Floor slab ............................................................ 63
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Table 4.28: Waste elimination for F.Floor column ....................................................... 64
Table 4.29: Waste elimination for F.Floor Slab ............................................................. 64
Table 4.30: Waste elimination processes for building for G.Floor ................................ 65
Table 4.31: Waste elimination in building for F.Floor................................................... 65
Table 4.31: Difference between activity before and after applying lean........................ 66
Table 4.33: Total project duration ................................................................................ 70
Table 4.34: Activities in a descending order based on duration..................................... 71
Table 4.35: Greatest duration of waste in activity.......................................................... 72
Table 4.36: Project duration without the most wasting activity .................................... .72
Table 4.37: Balancing the process .................................................................................. 74
Table 4.38: Cycle time compared................................................................................... 78
Table 4.39: Process assigned and process completed..................................................... 80
XI

List of Figures
Figure 2.1: Reduction of cycle time................................................................................ 11
Figure 2.2: Last Planner planning................................................................................... 18
Figure 2.3: Seven wastes ................................................................................................ 24
Figure 4.1: Procedure of the application of lean principles ................................ …..… 37
Figure 4.2: Application of lean to mobilization and excavation..................................... 52
Figure 4.3: Excavation process data ............................................................................... 53
Figure 4.4: Laboratory process data ............................................................................... 53
Figure 4.5: Application of lean to plain concrete ........................................................... 54
Figure 4.6: Formwork process data ................................................................................ 54
Figure 4.7: Casting plain concrete process data ............................................................. 55
Figure 4.8: Remove form work process data.................................................................. 55
Figure 4.9: Comparing value added steps to value added time ...................................... 68
Figure 4.10: Cause of failure .......................................................................................... 69
Figure 4.11:Simulation model ........................................................................................ 69
Figure 4.12: Duration variability before introducing buffer........................................... 73
Figure 4.13: Duration variability after introducing buffer.............................................. 78
Figure 4.14: Actual PPC of each week........................................................................... 80
Figure 4.15: Average PPC of each four week ................................................................ 81
XII

Chapter One
Introduction
Lean production was originally encapsulated within the Toyota Manufacturing System
and is well articulated by Womack (1990). Lean thinking subsequently became the
generic term to describe universal application beyond manufacturing (Womack and
Jones, 1996). The ideas of lean thinking comprise a complex amalgam of ideas
including continuous improvement, flattened organization structures, teamwork, the
elimination of waste, efficient use of resources and co-operative supply chain
management. Within the UK construction industry, the language of lean thinking has
become synonymous with the best practice. Confidence in these ideas remains so high
that the lean construction is an established component of construction best practice
(Green et al., 2005).
Lean construction much like current practice has the goal of better meeting customer
needs while using less of everything. But unlike current practice, lean construction rests
on production management principles. The result is a new project delivery system that
can be applied to any kind of construction but it is particularly suited for complex,
uncertain, and quick projects (Gregory et al., 1999).
Projects in the Gaza Strip are characterized by: low productivity, errors, poor coordination,
bad reputation, high accident rates, insufficient quality and overruns in cost
and schedule…etc.(Yahia, 2004).
The study was applied to a construction company, with wide experience in the field of
construction in Gaza Strip. The craftsmen with more than 10 years experience were met
so as to compare their productivity with that of those working at the Center National of
Animation Enterprises and Treatment of Information for Labor in Algeria. The reason
of lack of percent plan complete of work in the process, which means the rate of the
processes that were applied compared with that which should be applied, was defined
from the engineer in Abu Shahla office by using the five why tools of lean construction.
Finally, the result of applying lean construction, its methodology, and tools were
offered.
1

1.1 Statement of the Problem
Most of the construction projects in the Gaza Strip are characterized by inefficiencies,
large variability and low performance and thus wasting time, money and other resources
(Said, 2006). In this thesis, we will show the expected benefits of using some lean tools
in Gaza construction industry in order to reduce or eliminate waste and eventually
satisfy customer needs.
1. 2 Research Aim and Objectives
The aim of this research is to study the status quo of the application of lean construction
practices in the Gaza Strip and their implications on the performance. The aim of this
research can be divided into the following objectives:
1. To identify the criteria of lean as they apply to construction projects.
2. To identify basic lean tools for process improvement.
3. To identify methodology for application lean tools
4. To investigate the impact of lean practices.
1.3 Methodology Outline
The methodology used in undertaking the study has consisted of three stages:
1. Literature review including lean principles, lean tools and criteria of lean
construction.
2. A project was selected. Then, the processes and activities of the project were
analyzed using the daily reports. The duration and steps were found out.
3. Standardization and five why tools were applied on the project so as to reduce
the non value added process. Simulation was used to measure the impact of
value added.
Finally, results and recommendations are given.
1.4 Thesis contents
This thesis includes five chapters. Chapter One introduces the problem statement,
objectives and methodology outline. Chapter Two introduces literature review including
the history of lean construction, lean construction principles, lean construction criteria,
lean construction tools, and seven wastes. In chapter three, methodology is given in
2

details. Chapter Four analyzes case study data before and after applying lean tools.
Finally, conclusions and recommendations are given in Chapter Five.
3

2.1 Lean Construction History
Chapter Two
Lean Construction
The lean construction system initially appeared after the Second World War as
“Toyota system” or “lean manufacturing system”. Japan was defeated in the war, which
caused a lack of financial, physical and human resources thus resulting in the
superiority of American companies for the auto industry over Japanese companies by a
factor of 10 cars in production.
Then, Toyota leaders (Ohno and others), thought about the creation of this system
“Toyota system”.
Taiichi Ohno, who was given the task of developing a system that would
enhance productivity at Toyota, is generally considered to be the primary force behind
his system. Ohno chose some ideas from the west and particularly from Henry Ford’s
book “Today and tomorrow.” Ford’s moving assembly line of continuously flowing
material formed the basis for the Toyota production system. After some
experimentation, the Toyota production system was developed and was called “Just in
Time” between 1945 and 1970. Then the name was changed into “ Lean Production” as
the previous name seemed unsuitable. The system is still growing today all over the
world. The basic underlying idea of this system is to minimize the non value added.
In order to compete in today’s fiercely competitive market, US manufacturers
have come to realize that the traditional mass production concept has to be adapted to
the new ideas of lean manufacturing. A study that was done at the Massachusetts
Institute of Technology of the movement from mass production to world lean
manufacturing. The study underscored the great success of Toyota at NUMMI (New
United Motor Manufacturing Inc.) and brought out the huge gap that existed between
the Japanese and the western automotive industry. The ideas came to be adopted in the
US because the Japanese companies developed, produced and distributed products with
half or less human effort, capital investment, floor space, tools, materials, time, and
overall the expense (Abudallah et al., 2003).
4

The lean movement in construction started around 1992 with the creation of the
International Group of Lean Construction, which accepted the Ohno’s production
system design criteria as a standard of perfection. Since then, and especially over the
past decade, organizations all over the world have been looking for ways to increase
competitive advantage for the delivery of capital projects through the application of lean
concepts and techniques (Arbulu et al., 2006).
Today, there are an Arabic inclination towards the application of lean system in
the local projects where we find it in many productive projects: military clothing
industry as in Iraq which got a big success and a big production development. A lot
researches, masters and doctoral theses recommended to apply it at the Construction
projects level in the Arabic countries (Sameh, 2008).
2.2 Lean Construction Definition
Lean construction presents a coherent synthesis of the most effective techniques for
eliminating waste and delivering significant sustained improvement. in cost, time,
quality and safety simultaneously. In fact, lean construction has many definitions:
Ballard (2004) defines lean "added value by eliminating waste, being responsive to
change, focusing on quality, and enhancing the effectiveness of the workforce.
Typically, 95% of all lead time is non–value added". Ballard and Howell (2004) defined
it as “a temporary production system while delivering the product with maximum value
and minimum waste". whereas the lean construction institute (2003) defines lean
construction as, “a production management based approach to project delivery. Lean
production management has caused a revolution in manufacturing design, supply and
assembly. But Reiser (2000) defines lean construction as, "a project delivery system
based on the lean production management process, originally developed by the Toyota
Motor Company that is aimed at improving value by satisfying customer needs and
improving performance".
Finally, lean construction can be defined as added value by eliminating the waste of
space floor, material and the productivity of resources.
5

2.3 Impact of Lean Construction
According to (Colarelli Construction, 2005; Arbulu et al., 2006; Reiser et al., 2000),
lean construction provides key benefits and its impacts are as follows:
1. It delivers more value to the client with less waste of time and resources.
2. It helps contractors improve processes and overall project delivery.
3. It improves productivity by improving planning.
4. It helps accommodating change.
5. It reduces cost, accelerates delivery, and improves both quality and safety.
6. It delivers products or services on time and within budget.
7. It injects reliability, accountability, certainty, and honesty into the project
environment.
8. It reduces system noise.
9. It promotes continuous improvement in project delivery methods through
lessons learned.
2.4 Lean Construction Principles
Lean construction consists of the following five principles:
2.4.1 Value
The first and most critical lean principle as presented in lean thinking is value. Womack
and Jones(2003) emphasize that value can only be defined by the ultimate customer
and only meaningful when it is expressed in terms of a specific product (a good, or a
service, and often both at once) which meets the customer’s needs at a specific price
and specific time.
2.4.2 Value Stream
The second lean principle as presented in lean thinking is value stream, Womack and
Jones(2003) emphasize that value stream can only be defined by specific activities
required to design, order and provide a specific product from concept to launch, order to
delivery, raw material into the hands of the customer.
6

2.4.3 Flow
The third principle is flow, once all the wasteful activities are eliminated, the remaining
value-added steps need to ‘flow’. Conceptually companies have a difficult time
applying beyond internal departments. True integration of functions and departments in
a company into product teams organized along the value stream enables and promotes
flow of information and materials. Thus construction process is composed of two
different types of flows:
- Material process consisting of the flows of material to the site, including processing
and assembling on site.
- Work processes of construction teams. The temporal and spatial flows of construction
teams on site which are often closely associated with the material processes (koskela et
al., 1992).
2.4.4 Pull
The fourth lean principle as presented in lean thinking is pull, Womack and Jones(2003)
emphasize that pull can only be defined by implying the ability to design and make
exactly what the customer wants just when they want it. Nothing should be made until it
is needed, then it should be made quickly.
2.4.5 Perfection
The fifth lean principle as presented in lean thinking is perfection. Womack and Jones
(2003) emphasize that pull can only be defined by perfection implying the complete
elimination of waste. Important things to envision is the type of product and operating
technologies needed to improve.
The conceptualization of the lean in construction as developed by Björnfot (2006) is
shown in Table (2.1).
7

Table 2.1 Conceptualization of lean principle in construction (Björnfot, 2006).
No Lean principle Conceptualization in construction
1 Value
2 Value stream
3 Flow
4 Pull
5 Perfection
a) Define the customer.
b) Define what is value to the customer.
c) Define what is value to the delivery team.
d) Define how value is specified by products.
a) Define all and activities required for construction
b. Define all resources required for construction.
c) Standardize current practice.
d) Define and locate key component suppliers.
a) Identify none-value added activities (waste).
b) Remove or reduce the influence of waste as it is observed
c) Identify key performance indicators.
d) Measure performance.
a) Keep the production system flexible to customer
requirements.
b) Keep the production system adaptable to future customer
requirements.
c) Exercise a conscious effort at shortening lead and cycle
times.
d) Perform work at the last responsible moment.
a) Keep the production system transparent for all involved
stakeholders.
b) Capture and implement experience from completed
projects.
c) Exercise a conscious effort at improving value for
customers.
d) Exercise a conscious effort at improving the execution of
work.
8

2.5 Criteria of Lean Construction
Koskela (1992) applied lean production in the construction with eleven criteria which
are shown bellow:
2.5.1 Non-value added activities reduction
Reducing the share of non value-added activities is a fundamental guideline. Experience
shows that non value-added activities dominate most processes; usually only 3% to 20
% of steps add value (Ciampa et al., 1991), and their share of the total cycle time is
negligible, from 0.5 to 5 % (Stalk and Hout et al.,1990).
There are three main causes for the presence of non value-added activities:
• Construction Management: Non value-added activities are existed by
traditional management. Every time a task is subdivided into two subtasks
executed by different specialists, This leads to an expansion of the non valueadded
activities(such as : inspecting, waiting …etc) .
• Ignorance: Especially, it exists in the administration of construction. The
volume of non value-added activities is not measured. This requires contacting
with a project manager with a wide experience in dealing with the use of lean
tools.
• Seven wastes during construction: There are mistakes in the field or defects in
material.
2.5.2 Increase output value through systematic consideration of customer
This is considered the second criteria. Since value added is achieved according to
customer’s requirements without any exaggeration. Finding, for example the enterprise
companies are clients to the consultant. The consultant engineer’s office has to give the
design without any errors, the quantity of bidding cope with the design, the duration of
project is sensible. Considering the owner is a contractor’s customer, who aims to get a
building complied with specification of bidding, time schedule and costs as in the
contract.
2.5.3 Variability reduction
This is considered the third criteria. Schonberg (1986) says that “the reducing of
variation must be considered an essential aim”. So, having to measure the reasons of the
variation and work on reducing it, can be done by standardization. It works to measure
the rate of standardization of work per hour or day. So this can make master schedule
9

for measuring the percent plan complete (PPC) and look for the causes of failure. In
addition, PPC also helps to reduce the variation.
2.5.4 Cycle time reduction
The cycle time is the time required for executing the process traverse the construction
flow. The cycle time is used to measure the flow processes and it is a more useful than
cost and quality. It can be represented as follows:
Cycle time = Processing time + inspection time + wait time + move time
The new construction philosophy aims to compress the cycle time, which forces the
reduction of inspection, move and wait time.
In addition to the forced elimination of wastes, compression of the total cycle time gives
the following benefits: faster delivery to the customer, reduced need to make forecasts
about future demands, decrease of disruption of the construction process due to change
orders, easier management because there are fewer customer orders to keep track of.
The principle of cycle time compression also has other interesting implications:
1. From the perspective of control, it is important that the cycles of deviation detection
and correction be speedy.
2. In design and planning, there are many open-ended tasks that benefit from an
iterative search for successively better (if not optimal) solutions. The shorter the
cycle time, the more cycles are affordable.
3. From the point of view of improvement, every layer in an organizational hierarchy
adds to the cycle time of error correction and problem solving. This simple fact
provides the new construction philosophy’s motivation to decrease organizational
layers, thereby empowering the persons working directly within the flow.
Practical approaches to cycle time reduction include the following: Eliminating workin-progress
(this original JIT goal reduces the waiting time and thus the cycle time),
reducing storing time and setting temporary stores so that moving distances are
minimized, thus keeping things moving; smoothing and synchronizing the flows,
reducing variability, changing activities from sequential order to parallel order, and
eventually isolating the main value-added sequence from support work. In general,
solving the control problems and constraints prevents a speedy flow.
10

Figure (2.1) shows that the cycle time can be progressively compressed through
elimination of non value added activities and variability reduction.
Waste
time
Processing
time
Waste
time
Processing
time
Waste
time
Processing
time
Processing
time
Figure 2.1 Reduction of cycle time (Berliner and Brimson, 1988 )
2.5.5 Simplify by minimizing the number of steps and parts
The human ability to deal with complexity is restricted. This complexity of a product
increases non value-added activities. Complexity means the increase of the number of
steps in the production process. Reducing the number of steps leads to a reduction of
cost and an increase in reliability in the production process. Simplification can be
understood as, reducing of the number of components in a product, and reducing of the
number of steps in a material or information flow. Simplification can be realized, on the
one hand, by eliminating non value-added activities from the production process, and on
the other hand by reconfiguring value-added parts or steps. Organizational changes can
also bring about simplification. Vertical and horizontal division of labor always brings
about non value-added activities, which can be eliminated through self contained units
(multi-skilled, autonomous teams). Practical approaches to simplification include:
shortening the flows by consolidating activities, reducing the part count of products
through design changes or prefabricated parts, standardizing parts, materials, tools, etc.,
decoupling linkages, and minimizing the amount of control information needed.
11

2.5.6 Increase output flexibility
Flexibility should be limited during the period of construction. We can talk about it
from the duration of the project, for example, by using standardization of works, we can
add the number of resources to reduce the time, while the change in the activity affects
the project.
2.5.7 Increase process transparency
In a theoretical sense, transparency means a separation of the network of information
and the hierarchical structure of order giving, which in the classical organization theory
are identical. The goal is thus to substitute self-control for formal control and related
information gathering.
Transparency reduces errors and increases motivation for improvement. Thus, it is an
objective to make the production process transparent and observable for facilitation of
control and improvement: “to make the main flow of operations from start to finish
visible and comprehensible to all employees” (Stalk and Hout 1989). This can be
achieved by making the process directly observable through organizational or physical
means, measurements, and public display of information.
Practical approaches for enhanced transparency include the following:
� Establishing basic housekeeping to eliminate clutter.
� Making the process directly observable through appropriate layout and signage
� Rendering invisible attributes of the process visible through measurements
� Embodying process information in work areas, tools, containers, materials and
information systems
� Utilizing visual controls to enable any person to immediately recognize
standards and deviations from them.
� Reducing the interdependence of production units (focused factories).
2.5.8 Focus control on the complete process
There are two causes of segmented flow control: the flow traverses different units in a
hierarchical organization or crosses through an organizational border. In both cases,
there is a risk of sub optimization.
There are at least two prerequisites for focusing control on complete processes. First,
the complete process has to be measured. Secondly, there must a controlling authority
for the complete process. Several alternatives are currently used. In hierarchical
12

organizations, process owners for cross-functional processes are appointed, with
responsibility for the efficiency and effectiveness of that process (Rummler et al.,
1990). A more radical solution is to let self-directed teams control their processes
(Stewart et al., 1992).
For inter-organizational flows, long term co-operation with suppliers and team building
has been introduced with the goal of deriving mutual benefits from an optimized total
flow.
2.5.9 Build continuous improvement into the process
The effort to reduce waste and to increase value is an internal, incremental, and
iterative activity that can and must be carried out continuously. There are several
necessary methods for institutionalizing continuous improvement; these include the
following:
� Measuring and monitoring improvement.
� Setting stretch targets (e.g. for inventory elimination or cycle time
reduction), by means of which problems are unearthed and their solutions
are stimulated.
� Giving responsibility for improvement to all employees; a steady
improvement from every organizational unit should be required and
rewarded.
� Using standard procedures as hypotheses of best practice, to be constantly
challenged by better ways.
� Linking improvement to control: improvement should be aimed at the
current control constraints and problems of the process. The goal is to
eliminate the root of problems rather than to cope with their effects.
2.5.10 Balance flow improvement with conversion improvement
In the improvement of productive activities, both conversions and flows have to be
addressed; however, the question is how these two alternatives should be balanced.
For any production process, the flow and conversion aspects have a different
potential for improvement. This goes as a rule:
� The higher the complexity of the production process, the higher the impact
of flow improvement
13

� The more wastes inherent in the production process, the more profitable is
flow improvement in comparison to conversion improvement.
However, in a situation where flows have been neglected for decades, the potential
for flow improvement is usually higher than conversion improvement. On the
other hand, flow improvement can be started with smaller investments, but usually
requires a longer time than a conversion improvement.
The crucial issue is that flow improvement and conversion improvement are
intimately interconnected:
� Better flows require less conversion capacity and thus less equipment
investment
� More controlled flows make implementation of new conversion technology
easier
� New conversion technology may provide smaller variability, and thus flow
benefits.
Therefore, one is tempted to agree with Ohno, who argues that “improvement
adheres to a certain order” (Ohno, 1988). It is often worthwhile to aggressively
pursue flow process Improvement before major investments in new conversion
technology: “Perfect existing processes to their full potential before designing new
ones” (Blaxill et al., 1991). Later, technology investments may be aimed at flow
improvement or redesign.
2.5.11 Benchmark
Unlike technology for conversions, the best flow processes are not marketed to us; we
have to find the world class processes ourselves.
Often benchmarking is a useful stimulus to achieve breakthrough improvement through
radical reconfiguration of processes.
The basic steps of benchmarking include the following (Camp et al., 1989)
� Knowing the process; assessing the strengths and weaknesses of sub
processes.
� Knowing the industry leaders or competitors; finding, understanding and
comparing the best practices.
� Incorporating the best; copying, modifying or incorporating the best
practices in your own sub processes.
14

� Gaining superiority by combining existing strengths and the best external
practices.
2.6 Tools of Lean Construction
The lean construction tools which can be applied on the construction projects are:
2.6.1. Just in Time (JIT)
It is a philosophy that works in the elimination of waste in all activities and operations.
JIT system is a production cost system in the specified time for certain productivity
within the project; productivity which leads to its development and reduce its costs.
It is an inventory costs system in a timely manner, which works on receiving materials
today and use them tomorrow and this can be effected by adjusting the time of material
receipt at the time we start using it in production and adjusting the time of completion
with the time we delivered to customer. This represents a step in controlling stocks
systems leading to a JIT process.
On this basis, the adjusting time system which is working in production cost reduction
is by reducing the supply periods.
The most important JIT goals:
• Dispensing with all types of stock or reduced to a minimum.
• Reducing the wastage of time and resources in the productive processes.
• Purchasing in the appropriate time and quantities to meet consumer needs in a
timely and quality Occasion.
• The development of trust and relationship between the company and suppliers
through the development of long-term goals that lead to confidence
To deduce the problems and disadvantages of production costs at the time specified as
follows:
1. Difficulty of achieving some assumptions, such as the absence of defects in
production, as well as reaching level units with zero. Fault, along with zero
inventory, means difficulty in achieving it in large-scale company or companies
with seasonal activity.
2. This system requires substantial cooperation among management, workers and
suppliers, and we cannot apply this system without integration among those parties.
15

3. System requires the need to develop general accounting systems, special cost
system, and general costs concepts System.
4. Some company do not accept the idea of the application of the system of
production costs in time because of its high cost, which occur at the beginning of the
application of this system by the preparation of administrators and workers and by
changing company dealings with both suppliers and customers.
5. Administrators are not convinced about the change from existing systems to a
system of production costs in time because they fear its application failure.
6. Closures is the biggest problem facing the economic side to provide materials as the
stock in this system is equal to zero, and in the case of the closure, we will not find
materials to be used by the contractor and consequently activities are halted.
2.6.2 Last Planner System
Ballard (2000) indicates that Last Planner System (LPS) is a technique that shapes
workflow and addresses project variability in construction. The Last Planner is the
person or group accountable for operational planning, that is, the structuring of product
design to facilitate improved work flow, and production unit control, that is, the
completion of individual assignments at the operational level. In the last planner system,
the sequences of implementation (master schedule, Reverse Phase Schedules (RPS),
six-week look ahead, Weekly Work Plan (WWP), Percent Plan Complete (PPC),
constraint analysis and variances analysis).
The goals of last planner are to pull activities by reverse phase scheduling through team
planning and optimize resources in the long-term. This tool is similar to the Kanban
system and production leveling tools in lean manufacturing.
2.6.2.1 Master Schedule
The master schedule is an overall project schedule, with milestones, that is usually
generated for use in the bid package. RPS is produced based on this master schedule.
2.6.2.2 Reverse Phase Scheduling (RPS)
Ballard and Howell (2003) indicated that a pull technique is used to develop a schedule
that works backwards from the completion date by team planning; it is also called
Reverse Phase Scheduling (RPS). They also state that phase scheduling is the link
between work structuring and production control, and the purpose of the phase schedule
16

is to produce a plan for the integration and coordination of various specialists’
operations.
The reverse phase schedule is developed by a team consisting of all the last planners. It
is closer to reality than the preliminary optimal schedule which is the master schedule.
However, without considering actual field factors in the RPS, the RPS is less accurate
than the WWP.
2.6.2.3 Six-Week Look Ahead (SWLA)
Ballard (2000) indicated that the tool for work flow control is look ahead schedules.
SWLA shows what kinds of work are supposed to be done in the future. In the look
ahead window, week 1 is next week, the week after the WWP meeting. The number of
weeks of look ahead varies. For the design process, the look ahead window could be 3
to 12 weeks (Ballard 2000). All six-week-look ahead durations and schedules are
estimated based on the results of the RPS, and constraints are indicated in order to solve
the problems before the actual production takes place. SWLA is distributed to all last
planners at WWP meetings. Lean look ahead planning is the process to reduce
uncertainty to achieve possible constraint free assignments (Koskela et al., 2000).
2.6.2.4 Weekly Work Plan (WWP)
Should, Can, and Will are the key terms in WWP (Ballard 2000). Weekly Work Plan
(WWP) is produced based on SWLA, the actual schedule, and the field condition before
the weekly meeting. Along with this plan, manpower from each trade will be adjusted to
the need.
• Should: Indicates the work that is required to be done according to schedule
requirements.
• Can: Indicates the work which can actually be accomplished on account of
various constraints on the field.
• Will: Reflects the work commitment which will be made after all the constraints
are taken into account.
The WWP meeting covers the weekly schedule, safety issues, quality issues, material
needs, manpower, construction methods, backlog of ready work, and any problems that
can occur in the field. It promotes two-way communication and team planning to share
information on a project in an efficient and accurate way. It can improve safety, quality,
17

the work flow, material flow, productivity, and the relationship among team members.
Ballard and Howell (2003) indicates that WWP should emphasize the learning process
more by investigating the causes of delays on the WWP instead of assigning blames and
only focusing on PPC values. Variance analysis is conducted based on the work
performance plan from the previous week. The causes of variance should be
documented within the WWP schedule (Figure 2.2)
CAN
SHOULD
LAST PLANNER
PLANNING
Figure 2.2 Last Planner planning
WILL
2.6.2. 5 Percent Plan Complete (PPC)
The measurement metric of Last Planner is the Percent Plan Complete (PPC) values. It
is calculated as the number of activities that are completed as planned divided by the
total number of planned activities (Ballard 2000). The positive (upward) slope between
two PPC values means that production planning was reliable and vice versa. According
to Ballard (1999), PPC values are highly variable and usually range from 30% to 70%
without lean implementation. To achieve higher values (70% and above), additional
lean construction tools such as first run studies have to be implemented.
2.6.3 Increased Visualization
The increased visualization lean tool is about communicating key information
effectively to the workforce through posting various signs and labels around the
construction site. Workers can remember elements such as workflow, performance
targets, and specific required actions if they visualize them (Moser and Dos Santos
2003). This includes signs related to safety, schedule, and quality. This tool is similar to
18

the lean manufacturing tool, Visual Controls, which is a continuous improvement
activity that relates to the process control
2.6.4 First Run Studies
First Run Studies are used to redesign critical assignments (Ballard and Howell et al.,
1977), part of continuous improvement effort; and include productivity studies and
review work methods by redesigning and streamlining the different functions involved.
The studies commonly use video files, photos, or graphics to show the process or
illustrate the work instruction. The first run of a selected craft operation should be
examined in detail, bringing ideas and suggestions to explore alternative ways of doing
the work. A PDCA cycle (plan, do, check, act) is suggested to develop the study: Plan
refers to select work process to study, assemble people, analyze process steps,
brainstorm how to eliminate steps, check for safety, quality and productivity. Do means
to try out ideas on the first run. Check is to describe and measure what actually happens.
Act refers to reconvening the team, and communicating the improved method and
performance as the standard to meet.
2.6.5 Daily Huddle Meetings (Tool-box Meetings)
Two-way communication is the key of the daily huddle meeting process in order to
achieve employee involvement. With awareness of the project and problem solving
involvement along with some training that is provided by other tools, employee
satisfaction (job meaningfulness, self-esteem, sense of growth) will increase. As part of
the improvement cycle, a brief daily start-up meeting was conducted where team
members quickly give the status of what they had been working on since the previous
day's meeting, especially if an issue might prevent the completion of an assignment
(Schwaber, 1995). This tool is similar to the lean manufacturing concept of employee
involvement, which ensures rapid response to problems through empowerment of
workers, and continuous open communication through the tool box meetings.
2.6.6 The 5s Process (Visual Work Place)
• Sort
The first level of housekeeping consisted of separating material by reference and
placing materials and tools close to the work areas with consideration of safety and
crane movements.
19

• Straighten
Next, materials were piled in a regular pattern and tools were placed in gang boxes.
Each subcontractor took responsibility for specific work areas on the job site.
• Standardize
The next level included the preparation of a material layout design. The layout
contained key information of each work activity on the job site. The visual
workplace helped locate incoming material, reduce crane movements, and reduce
walking distance for the crews.
• Shine
The next step consisted of keeping a clean job site. Workers were encouraged to
clean workplaces once an activity had been completed. A housekeeping crew was
set to check and clean hidden areas on the job site.
• Sustain
The final level of housekeeping sought to maintain all previous practices throughout
the project. At the end of the project, this level is not fully achieved, in part because
project personnel did not view housekeeping as a continuous effort. They had to be
reminded frequently of housekeeping practices.
Table 2.2 resumes 5S purpose and goals.
Table 2.2 5S Purpose and Goals
5S Elements Purpose Goals
Sort
Set in Order
Shine
Eliminating what is not
needed
Creating the most
effective physical layout
possible
Establish a clean
environment
20
• Eliminate unnecessary items.
• Create means to keep them out of the
environment.
• Regain valuable space.
• Eliminate safety hazards caused by
clutter.
• Produce more positive environment.
• Design space that supports work
flow.
• Create a structure that supports
neatness.
• Organize tools, equipment, and
materials in a way that facilitates
efficient operations.
• Remove clutter, debris from
environment.
• Identify problems through inspection
and initiate a correction process.

Table 2.2 5S Purpose and Goals (cont.)
5S Elements Purpose Goals
Standardization
Sustain
2.6.7 Fail-Safe for Quality
• Check for Quality
Creating standard ways of
doing/storing things so
anyone can di/find anything.
Integrating 5S principles into
the culture of the
organization
• Establish standards that describe how
things should exist.
• Establish communication devices so
that everyone may understand how
things work.
• Form 5S habits.
• Integrate 5S into the organization's
culture. become s the way things are
done around here.
An overall quality assessment was completed at the beginning of the project. Most
quality issues could be addressed by standard practices, and it seemed there was
little room for improvement. During the execution of the project, however, some
critical items appeared such as a new vibration method for shearing walls was
suggested and implemented by the superintendent of the project.
• Check for Safety
Safety was tracked with safety action plans, i.e., lists of main risk items prepared by
each crew. Potential hazards were studied and explored during the job. Most
hazards, such as eye injuries, falls and trips, and hearing loss, have standard
countermeasures; however, in practice, workers have to be reminded of safety
practices (Salem et al., 2006).
2.6.8 Productivity Standardization
Productivity is a measure of how much we produce per unit input. From a client's
perspective, higher productivity leads to lower costs, shorter construction programs,
better value for money and a higher return on investment (Malcolm et al., 2001).
Contractors’ profits from increases in productivity are generally in the range of 2% to
4% of turnover. The increase in labor productivity by 25% would increase their profit
margins from 2% to 8%, or from 4 % to 10%, a two and a half to fourfold increase in
profit.
Partial Productivity = Total Output / (1) Input
Labour Productivity =Total Output / Number of labor
21

Material Productivity = Total Output / Amount of Material
Machine Productivity = Value of production / Amount of work (Yahia, 2004).
2.6.9 The Five Why's:
Five whys as part of lean manufacturing is a problem solving technique that allows you
to get at the root cause of a problem fairly quickly. It was made popular as part of the
Toyota Production System (1970’s.) Application of the strategy involves taking any
problem and asking “Why - what caused this problem”.
The benefits of the 5 Whys are as follows:
• It helps to quickly identify the root cause of a problem.
• It helps determine the relationship between different root causes of a problem.
• It can be learned quickly and does not require statistical analysis to be used.
2.7 Construction Waste
A number of definitions of waste are available. In general, Alarcon (1994), Koskela
(1992) and Love et al. (1997) argued that all those activities that produce costs, direct or
indirect, and take time, resources or require storage but do not add value or progress to
the product can be called waste. These waste categories are measured as a function of
their costs, including opportunity costs. Furthermore, other types of waste are related to
the efficiency of process, equipment or personnel.
Non value-added activity (also called waste): Activity that takes time, resources or
space but does not add value.(koskela et al., 1992).
Waste in the construction industry has been the subject of several research projects
around the world in recent years (Formoso et al., 1999). The study by Skoyles (1987) in
the UK also suggested that all those involved in the construction process contributed to
waste. This includes those who design materials, plant and building; those who specify
and communicate, for example, the quantity surveyors and head office staff; and
particularly site managers and site operators.
Therefore, the responsibility for minimizing waste should be shared by all parties
involved in construction projects, including:
• All managers in building organizations, not only site managers,
• Those who design, manufacture and supply merchandise and plant used in
construction,
22

• Those who design buildings,
• Those who specify, describe and account for the works, and
• Those who provide briefs pay for and use buildings.
Graham and Smithers (1996) believed that construction waste could occur during
different project phases:
• Design (plan errors, detail errors and design changes),
• Procurement (shipping error and ordering error),
• Materials handling (improper storage, deterioration and improper handling on and
off site)
• Operation (human error, trades person, labors, equipment error, accidents and
weather),
• Residual (leftover and irreclaimable non-consumables), and
• Other (theft, vandals and clients actions).
Despite variations in construction projects, potential material waste is caused by similar
inefficiencies in design, procurement, material handling, operation or residual on-site
waste such as packaging (Formoso et al., 1993 and Gavilan and Bernold, 1993).
Research also indicated that clients could be a source of waste through careless
inspection procedures and variation orders during the process. Initially, carelessness at
the design stage can lead to excessive waste which creates a need to over order to avoid
a shortage of materials on site (Graham and Smithers, 1996). Waste in construction is
not only focused on the quantity of waste of materials on-site, but also related to several
activities such as overproduction, waiting time, material handling, processing,
inventories and movement of workers (Formoso et al., 1999; Alarcon, 1994).
Consolidating research from authors (Alarcon, 1995; Alwi, 1995; Koskela, 1993;
Robinson, 1991; Lee et al., 1999; Pheng and Hui, 1999), the main categories of waste
during the construction process can be described as: reworks/repairs, defects, material
waste, delays, waiting, poor material allocation, unnecessary material handling and
material waste. In Chile, a research study from 1990 to 1994, focusing on waste was
conducted to identify the most relevant factors that produce waste of productive time in
building construction works (Serpell et al., 1995). The study concluded that waiting
time, idle time and travelling time, indicated as the main subcategory of noncontributory
work (waste), explained 87% of the total value of waste. Another
23

investigation showed that 25 percent time savings is achievable in a typical construction
work package without increasing allocated resources (Mohamed et al., 1996).
Lean construction maximizes value and reduces waste and applies specific techniques in
an innovative project delivery approach including supply chain management and Just-
In-Time techniques as well as the open sharing of information between all the parties
involved in the production process. Lean manufacturing is an outgrowth of the Toyota
Production system that was developed by Taichii Ohno in Toyota in the 1950s. Ohno
identified seven wastes in mass production systems (Figure 2.3).
Waiting time
Defects
Overprocessing
Overproduci
ng
The seven
wastes
Figure 2.3 Seven wastes
24
Motion
Inventory
Material
Movement

2.8 Construction Waste in the Gaza Strip
According to Said (2006), construction wastes Gaza Strip are classified according to
the seven wastes as follows:
2.8.1 Over-production
Over-production is unnecessarily producing more than demanded or producing it too
early before it is needed. This increases the risk of obsolescence, increases the risk of
producing the wrong thing and increases the possibility of having to sell those items at a
discount or discard them as scrap. However, there are some cases when an extra supply
of semi-finished or finished products is intentionally maintained, even by lean
manufacturers.
Over-production waste of construction in the Gaza Strip is due to:
1. Ordering of materials that do not fulfill project requirements defined on design
documents, and waiting for replacement.
2. Over ordering or under ordering due to mistake in quantity surveys.
3. Over ordering or under ordering due to lack of coordination between warehouse
crews and construction crews.
2.8.2 Defects: (Correction)
In addition to physical defects which directly add to the costs of goods sold, this may
include:
errors in paperwork, provision of incorrect information about the product, late delivery,
production to incorrect specifications, use of too much raw materials or generation of
unnecessary scrap, repair or rework wastes time and resources at every level of the
organization, correction means doing it twice which doubles an employee’s exposure to
risk
Defects waste of construction in the Gaza Strip is due to :
1. Damage materials on site.
2. Unnecessary inventories in site which lead to waste.
3. Manufacturing defects.
4. Poor quality of materials.
5. Use of incorrect material, thus requiring replacement.
6. Equipment frequently breakdown.
25

7. Poor technology of equipment.
8. Shortage of tools and equipments required.
10. Rework due to workers’ mistakes.
11. Damage to work done caused by subsequent trades.
12. Poor workmanship.
2.8.3 Inventory
Inventory waste means having unnecessarily high levels of raw materials, work-inprogress
and finished products. Extra inventory leads to higher inventory financing
costs, higher storage costs and higher defect rates.
Inventory hides waste and defects as materials that have been fabricated and stored for
various projects, backlog of good work over jobs, a batch of engineering
recommendations, and massive amounts of data being stored for use at a later date or
never used at all.
Inventory waste of construction in the Gaza Strip is due to:
1. Wrong storage of materials.
2. Inadequate stacking and insufficient storage on site.
3. Insufficient instructions about storage and stacking.
4. Inappropriate storage leading to damage or deterioration.
2.8.4 Transportation: (Material Movement)
Transportation includes any movement of materials that does not add any value to the
product, such as moving materials between workstations. The idea is that transportation
of materials between productions stages should aim for the ideal that the output of one
process is immediately used as the input for the next process. Transportation between
processing stages results in prolonging production cycle times, the inefficient use of
labor and space and can also be a source of minor production stoppages. Unnecessarily
moving materials wastes
time, energy, resources, and increases the likelihood of injury such as moving work-inprocess
from a site to site, moving an engineering recommendation from one area to
another for review, moving pipe from location to location.
Transportation waste of construction in the Gaza Strip is due to:
1. Damage during transportation
2. Use of inadequate tools and equipments
26

3. Poor storage
4. Far distance between place of working and storage.
5. Unpacked supply (fragile).
2.8.5 Waiting
Waiting is idle time for workers or machines due to bottlenecks or inefficient
production flow on the factory floor. Waiting also includes small delays between
processing of units. Waiting results in a significant cost insofar as it increases labor
costs and depreciation costs per unit of output are in general known as: waiting for
parts, waiting for decisions or direction, waiting for data or information, waiting for
recommendation and waiting for supplies.
Waiting waste of construction in the Gaza Strip is due to:
1. Waiting for design documents and drawings Motion.
2. Rework that don't comply with drawings and specifications.
3. Rework due to workers’ mistakes.
4. Delays in passing of information to the contractor on products.
5. Waiting for workers or materials or equipments to arrive.
6. Equipment frequently breakdown.
7. Delay in commencement of project.
8. Delay in performing inspection and testing by the consultant engineer.
9. Suspension of work by the owner.
10. Change orders.
2.8.6 Motion
Motion includes any unnecessary physical motions or walking by workers which diverts
them from actual processing work. For example, this might include walking around the
factory floor to look for a tool, or even unnecessary or difficult physical movements,
due to poorly designed ergonomics, which slow down the workers. Unnecessary
movement (walking, reaching, lifting, etc.) wastes time and energy such as walking
back and forth between equipment and a truck to get tools or parts, walking back and
forth between the drawing table and a document storage area to get information, going
to a warehouse to get parts
Motion waste of construction in the Gaza Strip is due to:
1. Poor schedule to procurement the materials.
27

2. Unnecessary material handling.
3. Tradesmen slow/ineffective.
4. Far distance between place of working and storage.
5. Poor distribution of materials in site.
6. Lack of proper maintained pathways.
7. Difficulty in motion of worker in the site
2.8.7 Over-processing
Over-processing is unintentionally doing more processing work than the customer
requires in terms of product quality or features – such as polishing or applying finishing
on some areas of a product that won’t be seen by the customer. Doing more work tends
to keep people “busy,” but adds no “value” such as writing a comprehensive legal
agreement when a simple agreement would suffice, replacing more parts than necessary,
spending extra time doing more analysis than is really necessary, unnecessary
complexity.
Over-processing waste of construction in the Gaza Strip is due to:
1. Conversion waste from cutting uneconomical shapes.
2. Using excessive quantities of materials more than the required.
3. Wrong handling of materials.
4. Insufficient instructions about handling.
5. Lack of workers or tradesmen or subcontractors’ skill.
6. Difficulty in performance and professional work.
7. Interaction between various specialists.
8. Using untrained labors
28

2.9 Summary
The lean construction takes its idea from the lean manufacturing by making customer’s
needs as the main priority of the company objectives. The application of lean
construction started in 1992 by International Group of Lean Construction. The main
objective of lean construction is to increase the value added activities and remove or
reduce the non-value added activities in the project. The impact of lean construction
gives more value to the client with less waste of time and resources. It helps contractors
improve processes and overall project delivery, improve productivity by improving the
planning. The impact is also an approach well suited to accommodate change, reduces
cost, accelerates delivery, improves both quality and safety, delivers products or
services on time and within budget. It also injects reliability, accountability, certainty,
and honesty into the project environment and reduces system noise, improves project
delivery methods and promotes continuous improvement in project delivery methods
through lessons learned. Lean thinking consist of five points: Value, value stream, flow,
pull and perfection. Koskela (1992) applied lean production in the construction with
eleven criteria which are: non-value-added activities reduction, increase output value,
variability reduction, cycle times reduction, simplifies by minimizing the number of
steps, increase output flexibility, increase process transparency, benchmark, build
continuous improvement into the process, balance flow improvement with conversion
improvement and focus control on the complete process. The lean construction tools
are: Just in time (JIT), last planner system, increased visualization, first run studies,
productivity, the 5S process, fail-safe for quality, the 5 why's and daily huddle meetings.
The seven wastes according to the research thesis of the construction wastes in the
Gaza Strip (Said, 2006) are: over-production (ordering of materials that do not fulfill
project requirements defined on design documents, and waiting for replacement, over
ordering or under ordering due to a mistake in quantity surveys, over ordering or under
ordering due to lack of coordination between warehouse and construction crews),
defects (damage materials on site, unnecessary inventories in site which lead to waste,
poor quality of materials, use of incorrect material, thus requiring replacement,
equipment frequently breakdown, poor technology of equipment, shortage of tools and
equipments required, rework due to workers’ mistakes, damage to work done caused by
subsequent trades, poor workmanship and choice of wrong construction method ),
29

inventory (Wrong storage of materials. Inadequate stacking and insufficient storage on
site, insufficient instructions about storage and stacking and inappropriate storage
leading to damage or deterioration), transportation (damage during transportation, use
of inadequate tools and equipments, poor storage, far distance between place of working
and storage and unpacked supply), waiting (waiting for design documents and drawings
motion, rework that does not comply with drawings and specifications, rework due to
workers’ mistakes, delays in passing of information to the contractor on products,
waiting for workers or materials or equipments to arrive, equipment frequently
breakdown, delay in commencement of project, delay in performing inspection and
testing by the consultant engineer and suspension of work by the owner and change
orders ), motion (poor schedule to procurement the materials, unnecessary material
handling, tradesmen slow/ineffective, far distance between place of working and
storage, poor distribution of materials in site, lack of proper maintained pathways, and
difficulty in motion of worker in the site ) and over-processing (conversion waste from
cutting uneconomical shapes, using excessive quantities of materials more than the
required, wrong handling of materials, insufficient instructions about handling, lack of
workers or tradesmen or subcontractors’ skill, difficulty in performance and
professional work, interaction between various specialists and using untrained labors).
In this thesis, we shall work on achieving the largest number of lean construction
criteria because the project which was studied was completed. Waste in the value added
process and non-value added process will be eliminated or reduced. These wastes are
particularly found in the project that was studied. Standardization and five why were the
chosen tools to apply and implement lean construction in the Gaza Strip.
30

Chapter Three
Methodology
This chapter presents the methodology which was followed in this research.
3.1 Research Strategy
Quantitative and qualitative methods are used in this thesis. Quantitative data has been
collected to measure the proportion of non-value added and the value added for time
and steps in each process. This was measured by standardization tools, while qualitative
data was used in order to understand the reasons of non-value added in the process by
using the five why tools and giving solutions and suggestions for reducing the nonvalue
added in construction.
3.2 Data Collection
To achieve the objectives of the current study, the researcher has used several sources.
These include:
3.2.1 Primary Sources
Productivity data was obtained for Yahia (2004). Moreover 30 crafts men who have
more than 10 years experience were interviewed. The results obtained were compared
with productivity data reported in the Center National of Animation Enterprises and
Treatment of Information for Labor in Algeria Company. Minimum, the most likely and
the maximum productivity of the resources are shown in (Table 3.1). In addition, the 5
why were used to determine the causes of waste.
31

Main
Activity
Mobilization
and excavation
Plain concrete
Foundation
work
Neck column
Back filling
Ground beam
Column work
Ground floor
Slab work
Table 3.1 Productivity of resources in Gaza Strip
Activity
process
Excavation work M 3
Form work M 3
Cast plain concrete M 3
Remove form work M 3
Form work M 3
Fix neck column M 3
Cast foundation M 3
Remove form work M 3
Form work M 3
Cast concrete M 3
Remove form work M 3
First layer M 3
Second layer M 3
Final layer M 3
Form work M 3
Cast concrete M 3
Remove form work M 3
Fix steel column M 3
Form work M 3
Cast concrete M 3
Remove form work M 3
Preparation work M 2
Steel work M 2
Mechanic work M 2
Cast concert M 2
Form work M 2
Hollow cement
Block work
M 2
Steel work M 2
Electric work M 2
Cast concrete M 2
Remove form work M 2
Unit Minimum
32
Unit/hours
Most
likely
Maxim
um
57.69 62.5 68.18
0.625 0.875 1
0.75 0.875 1
0.58 0.7 0.875
0.625 0.875 1.125
0.648 0.81 1.08
5.77 6.5 12
2.62 3.25 4.31
0.072 0.083 0.147
0.083 0.1 0.125
0.31 0.375 0.46
17.85 20.8 22.3
25 31.25 41.66
25 31.25 41.66
0.28 0.4 0.58
0.083 0.1 0.125
0.7 0.93 1.125
1.81 2.26 3
0.176 0.2 0.35
0.4 0.48 0.6
1.51 1.81 2.26
33.33 36.36 40
14.28 14.81 15.38
66.7 80 100
66.7 80 100
6.55 7.37 8.42
9.83 11.8 14.75
6.55 7.37 8.42
6 8 12
8 9 10
4.91 5.9 7.37

Main
Activity
Building work
3.2.2 Secondary Sources
Table 3.1 Case study productivity (Cont.)
Activity
process
Building under the
window
M 2
Lintel work under
window
ML
Cast lintel under the
windows
ML
Remove form work ML
Building behind the
widows
M 2
Lintel work behind
window
ML
Cast lintel up the
windows
ML
Remove form work ML
Building up the
window
M 2
Unit Minimum
Unit/hours
Most
likely
Maximum
2.07 2.17 2.38
15.91 19.1 23.87
47.75 63.66 95.5
23.87 31.83 47.75
2.65 2.8 3.18
15.91 19.1 23.87
47.75 63.66 95.5
47.75 31.83 93.87
2.07 2.17 2.38
The secondary sources include books, references, journals and magazines, and papers
related to the research subject.
3.3 Application of Lean Principles in Construction
Standardization was used to reduce the waste in the process by using the data of (Table
3.1). The five why tools were used to identify the causes of waste and reduce the
number of steps. The following ten points were used to define the biggest non- value
added process in the project by using arena simulation in order to reduce non value
added. More details of Arena Simulation are given in appendix (B).
1. Select all non value-added activities in the simulation model (candidates for
improvement). Use the definition provided by (Koskela, 1992) in the previous
section to focus on activities that do not add value to the operation.
2. Set the task durations of the improvement candidates to zero (one at a time).
Although, in many cases, eliminating these activities is not possible or practical,
doing so will allow one to determine their significance on the model output.
3. Produce simulation results (run the simulation).
33

4. Sort the candidates in order of their significance to the simulation model. This will
enable
the improvement process to focus on those activities that have the greatest impact on
model outputs.
5. Look for practical activity reduction solutions for the candidates, starting with the
activity that has the greatest potential for improvement.
6. Edit the simulation model to reflect zero-time delivery the biggest non value added
activities. Although this may not be possible or practical, it will allow one to
determine the effect on the project.
7. Produce simulation results (run the simulation).
8. Look for practical solutions to improve the material delivery processes (if required).
If the material delivery process has a significant impact on model outputs, efforts
should be made to make practical improvements.
9. Look for practical solutions to improve production activities. Only after the lean
concepts (value-added activities and pull-driven flow) have been introduced to the
model should the improvement be focused on production activities.
10. Introduce buffers to compensate for increased model variability and for differing
production rates of linked operations. The lean production improvement process has
generally been shown to introduce significant variability into processes. Buffers
should be introduced as a final step to compensate for this effect (Jack et al., 2004).
34

Chapter Four
Application
Lean has been applied on a completed construction project of the construction because
there is a lack of projects under construction. The project data are available and the
project is of a medium size. The lean tools (standardization) are applied on this project
and simulation has been applied to analyze the processes and activities duration.
4.1. Project Description
Table (4.1) shows information about the selected project.
Table 4.1 Details of project
No SUBJECT DATA
1 Project name -
2 Location -
3 Owner -
4 Contractor -
5 Sub contractor -
6
Design consultant
7 Site consultant -
8 Donor The Islamic development bank- Jeddah
9 Project area 3200 m 2
10 Basement floor area 2370 m 2
11 Ground floor area 2508 m 2
12 First floor area 2420 m 2
13 Start day 20/05/2004
14 Finish day 20/06/2006
15 Real project duration 750days
16 Contract duration 365 days
17 Estimated cost of project 2,331,834.00 $
35
-

4.2 Project Activities
Lean construction has been applied on the following project activities in mobilization,
plain concrete, foundation, neck column, isolation, back filling, ground beam works,
column for ground floor, ground floor, ground floor slab, first floor column, second
floor slab, building for ground floor, and building works for first floor. The execution of
the project is divided into three blocks A, B and C. Appendix (E).
4.3 Lean Criteria Procedure
The procedure of applying the lean principles is as follows:
• Defining the customer, the customer value, all resource required for construction,
and all activities required for construction.
• Identify non value added process (steps, time).
• Removing or reducing the wastes in process by using the standardization and the
five why tools to identify the cause of failure.
• Identifying non value added activities by applying the points in figure 4.1 on the
construction of El-Nasser New Pediatric Hospital project.
• Improving the project until reaching perfection.
The above procedures are applied to the project as follows:
The customer is the Ministry of Health. The value of customer is to construct the project
with the same duration and cost and specification of contract.
Only the following eight points in Figure (4.1) from the ten points in section (3.3) were
applied to the project because it is a completed construction project.
36

Setting the process durations of the improvement candidates
to zero (one at a time)
Producing simulation result(run the simulation)
Sorting the candidates in order of their significance to
the simulation model
Looking for practical activity reduction solutions
for the candidates, starting with the activity that has the
greatest potential.
Editing the simulation model to reflect zero-time on the
biggest non value added process.
Producing simulation results (run the simulation)
Looking for practical solutions to improve production activities. Only after
the lean concepts (value-adding activities and pull-driven flow) have been
introduced to the model should the improvement be focused on production
activities.
Introduce buffers to compensate for increased
model variability and for differing production
rates of linked operations.
Conclusion and recommendation
Figure 4.1 Procedure of the application of lean principles
37

Table 4.2 represents the resources, the duration for the process and the bill of the
quantities of project by using Table (3.1). The following resources are available
throughout all the project period: Project manager (1), Site engineer (2), Foreman (1),
Surveyor (1).
Calculation in the last column was done as follows:
Duration (hour) = Quantity/ ( Number of resources x Productivity x 8 hours)
Maximum duration of the excavation process = 6000/ (1x 57x 8)= 13 hours.
Most likely duration of the excavation process = 6000/ (1x 62x 8)= 12 hours.
Minimum duration of the excavation process = 6000/ (1x 68x 8)= 11 hours.
The remaining processes were calculated in the same way.
Main
Activity
Mobilizatio
n and
excavation
Plain
concrete
Foundation
Neck
column
Process
Table 4.2 Productivity of the project activities
Excavation
work
Uni
t
M 3
Form work M 2
Cast plain
concrete
Remove
form work
M 2
M2
Form work M 3
Fix neck
column
Cast
foundation
Remove
form work
Form work
Cast
concrete
Remove
form work
M 3
M 3
M3
M 3
M 3
M3
Quantity
6000
No.
resource
1
Excavator
Productivity/*
hour
57, 62, 68
140 5 workers 0.6, 0.8, 1
140 5 workers 0.7, 0.8, 1
140 5 workers 0.6, 0.7, 0.9
935 9 workers 0.6, 0.9, 1
935 9 workers 6, 8, 10
935 9 workers 6 , 7 , 12
935 9 workers 2, 3, 4
60 8 workers
60 8 workers
0.07, 0.08,
0.15
0.08, 0.1,
0.12
60 8 workers 0.3, 0.4, 0.5
Duration
1day=8h
11,12,13
days
3.5, 4.5.
5.5
days
4,5,6
hours
3, 4, 5
days
11.5, 15,
21 days
1.5,2, 2.5
days
12, 16,18
hours
3, 4, 5
days
51, 90,
103
hours
60, 75, 90
minute
16, 20, 24
hours
* This column shows the minimum, most likely and maximum productivities according
to the bill quantity of the project.
38

Main
Activity
Back filling
Ground beam
Column
work
Ground floor
Table 4.2 Productivity of the project activities(Cont.)
Process Unit
First
layer
M 3
Second
layer M 3
Final
layer
Form
work
Cast
concrete
Remove
form
work
Fix steel
column
Form
work
Cast
concrete
Remove
form
work
Preparati
on work
Steel
work
Mechanic
work
Cast
concrete
M 3
M 3
M 3
M 3
M 3
M 3
M 3
M 3
M 2
M 2
M 2
M 2
Quantity
1000
1000
1000
180
180
180
145
145
145
145
2000
2000
2000
2000
39
No.
resource
2
excavator
s
2
excavator
s
2
excavator
s
8
workers
8
workers
8
workers
4
workers
4
workers
4
workers
4
workers
5
workers
5
workers
5
workers
5
workers
Productivity
/hour
18, 21, 22
25, 31, 41
25, 31, 41
0.3, 0.4,
0.6
0.08, 0.1,
0,12
0.7, 0.9, 1
1.8, 2, 3
0.1, 0.2,
0.3
0.4, 0.5,
0.6
1.5, 1.8, 2
33, 36, 40
14, 15, 16
60, 80,
100
60, 80,
100
Duration
1day=8h
2.5, 3,3.5
days
1.5, 2, 2.5
days
1.5, 2, 2.5
days
4.5, 7, 10
days
60, 75,90
hours
2.5, 3, 4
days
1.5, 2, 2.5
days
102, 180,
206 hours
60, 75, 90
minute
16, 20, 24
hours
10, 11, 12
hours
26, 27, 28
hours
4, 5 ,6
hours
4, 5 ,6
hours

Main
Activity
Slab work
Building
work
Table 4.2 Productivity of the project activities(Cont.)
Process
Un
it
Form work M 2
Hollow cement
block
M 2
Steel work M 2
Electric work M 2
Cast concrete M 2
Remove form
work
Building under the
window
Lintel work under
window
Cast lintel under
the windows
Remove form
work
Building behind
the widows
Lintel work
behind window
Cast lintel up the
windows
Remove form
work
Building up the
window
M 2
M 2
M
L
M
L
M
L
M 2
M
L
M
L
M
L
M 2
Quantity
1180
1180
1180
1180
1180
1180
5730
5730
5730
5730
5730
5730
5730
5730
5730
40
No
resource
9
workers
9
workers
9
workers
4
workers
9
workers
9
workers
5
workers
5
workers
5
workers
5
workers
5
workers
5
workers
5
workers
5
workers
5
workers
Productiv
ity/
1hours
6, 7, 8
10, 12, 15
6, 7, 8
6, 8, 12
Duration
1day=8h
(3.5, 4, 4.5)
days
(2, 2.5, 3)
days
(3.5, 4, 4.5)
days
(6, 8, 12)
hours
8, 9, 10 8, 9, 10hour
5, 6, 7 4, 5, 6 days
2, 2.5 ,3
16, 19, 24
20, 22, 23
days
2, 2.5, 3
days
48, 64, 95 4, 6, 8 hours
24,32, 48
2.5, 2.8, 3
16, 19, 24
1, 1.5, 2
days
15, 17, 18
days
2, 2.5, 3
days
48, 64, 95 4, 6, 8 hours
24, 32, 48
2, 2.5 ,3
1, 1.5, 2
days
20, 22, 23
days

4.4. Non-Value Added and Value Added Process Identification
Activities can be classified as:
1. Activity that adds value and can be defined as follows:
• Activity which contributes to the customer's perceived value of the product
or service (Convey et al., 1991).
• Activity that “converts material and/or information towards what is required
by the customer” (Koskela et al., 1992).
2. Activity that does not add value and can be defined as follows:
• Activity which, if eliminated, would not detract from the customer's
perceived value of the product or service (Saukkorriipi et al., 2004).
• Activity which“takes time, resources and space but does not add value”
Koskela et al., 1992).
In the analysis of the project, the value added and non-value added times and steps of
the process can be defined as follows:
• Value added time is the time that increases the value duration of the process
without any waste.
• Non-value added time is the time that does not increase the value added of the
process without waste.
• Value added steps are the steps that increase the value of the work steps without
any kind of waste.
• Non-value added steps are the steps that do not increase the process value
without waste.
• Waste is a kind of seven wastes over- production, defects, inventory,
transportation, waiting, motion and over- processing.
Section 4.4.1 to 4.4.14 show the value and non value added processes of the project
activities. The non value added takes “0” whereas value added takes number “1” or a
fraction according to the number of the steps in a process. For example section (4.4.1)
the excavation process took two steps so the value added steps equal 1/2 +1/2 = 1. If the
excavation was performed in one step, the value added of step takes “1”.
41

4.4.1 Mobilization and excavation
Table (4.3) shows seven processes where the number of value added steps is 1 out of 7
steps which corresponds to14% of total steps. The total duration of the mobilization and
excavation in the daily report is 240 hours.
No.
Table 4.3 Value and non-value added processes in mobilization and excavation
Process
Step
number
Step
Value
added
steps
Duration
1day=
8hours
1 Site cleaning, includes removing trees 1 0 48
2 Demolishing the existing walling fence. 2 0 32
3 To setup the site engineer office 3 0 32
4
Excavation of the natural ground to the
required levels
4 1/2 96
5 Laboratory 5 0 8
6 Expand the excavation 6 1/2 16
7 Laboratory 7 0 8
Total 7 1
Percentage of value added steps 14%
240
4.4.2 Plain concrete
Table (4.4) shows the five processes that constitute the plain concrete. The number of
value added steps is 1 out of 5 steps (20%) and the total duration in the daily report is 63
hours.
Table 4.4 Non-value added and value added processes in plain concrete
No.
1
2
3
4
5
Process
Step
number
Steps
Value
added
steps
0
1/2
0
1/2
Cheblona work +form work concrete 1
Cast in site 10cm thick plain concrete 2
Rework form work for foundation concrete 3
Cast 3M3 plain concrete 4
Remove form work 5 0
Total 5 1
Percentage of value added steps 20%
42
Duration
(hours)
1day=
8hours
24
16
8
5
10
63

4.4.3. Foundation
Table (4.5) shows thirteen processes that constitute the foundation. Where the number
of value added steps is 2 out of 13 steps (15%) and the total duration in the daily report
is 276 hours.
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
Table 4.5 Non-value added and value added processes in foundation
Process
Form work foundation concrete part "C"
Form work foundation concrete part "A and
"B"
Fix steel of neck column part "A"
Fix neck steel of neck column "B"
Cast foundation "A"
Remove form work part "A"+ form work
part "C".
Fix steel neck column part "C"
Cast foundation part "B"
Steel work for foundation part "C"
Cast foundation part "B"
Remove form work part "C"+ part "B".
Form work for 5 foundation part "c", back
filling
Steel work +cast 5 foundation part "C" +
back filling + steel work + Laboratory
Total
Percentage of value added steps
43
Step
number
1
2
3
4
5
6
7
8
9
10
11
12
13
13
Step
15%
Value
added
steps
0
0
1/4
1/4
1/4
0
1/4
1/4
1/4
1/4
0
0
1/4
2
Duration/
hours
1day=8hou
rs
88
80
28
8
8
8
4
4
8
8
8
16
8
276

4.4.4 Neck column
Table (4.6) shows thirteen processes that constitute the neck column. The number of
value added steps is 1 out of 13 steps (7.6%) and the total duration in the daily report is
132 hours.
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
Table 4.6 Non-value added and value added processes in neck column
Process
Reinforced concrete
basement, remove walls form
work
Form work neck column ,
wall concrete
Justify the defect in the
column.
Cast wall concrete "A"
Form work "B"
Remove form work "A" neck
column wall concrete+ "
Neck column "B".
Cast neck column "B"+
Remove form work wall
Form work part " C"
Cast neck column part B.
Cast neck column part C
Remove form work +
Chaining
Total
Percentage of value added steps
Step
number
44
1
2
3
4
5
6
7
8
9
10
11
12
13
13
Step
Value
added steps
7.6%
0
0
0
0
0
0
0
1/3
0
0
1/3
1/3
0
1
Duration
(hours)
1day=
8hours
2
8
54
4
2
8
8
16
2
8
10
2
8
132

4.4.5 Isolation
Table (4.7) shows two processes that constitute the isolation. The number of value
added steps is 1 out of 2 steps (50 %) and the total duration in the daily report is 48
hours.
No.
1
Table 4.7 Non-value added and value added processes in isolation processes
Cleaning
Process
2 Cleaning , isolation work
Total
Percentage of value added steps
4.4.6 Back filling
Step
number
1
2
2
Steps
50%
Value
added
steps
0
1
1
Duration (hours)
1day=8hours
The six processes that represent backfilling are shown in Table (4.8). The number of
value added steps is three out of six steps (50%) and the total duration in the daily report
is 112 hours.
Table 4.8 Non-value added and value added processes in back filling
No.
1
2
3
Process
Back filling layer1 + cleaning
Laboratory
Back filling layer 2
4 Laboratory
5 Back filling layer 3
6 Laboratory
Total
Percentage of value added steps
Step
number
45
1
2
3
4
5
6
6
Step
50%
Value
added
steps
1
0
1
0
1
0
3
8
40
48
Duration
1day=8hours
Duration
Of process/
hours
48
8
32
4
16
4
112

4.4.7 Ground beam
The twelve processes that represent ground beam are shown in Table (4.9). The number
of value added steps is 6 out of 12 steps (50%) and the total duration in the daily report
is 192 hours.
Table 4.9 Non-value added and value added processes in ground beam
No.
1
2
3
4
5
6
7
8
9
10
11
12
Step
Process
Step Value
number added
steps
Form work for ground beam part A 1 0
Form work for ground beam part B 2 0
Back filling 3 1
Form work for ground beam part C 4 0
Steel work
5 1
Mechanical work
6 1
Earth electric
7 1
Caste ground part A,C
8 1/2
Remove form work part A
9 0
Isolation work
10 1
Cast G. beam part B
11 1/2
Remove form work
12 0
Total
12 6
Percentage of value added steps
50%
4.4.8 Ground floor column
Duration
(hours)
1day=8hours
Table (4.10) shows nineteen processes where the number of value added steps is 2 out
of 18 steps (10%) and the total duration of ground floor column in the daily report is
346 hours.
Table 4.10 Non-value added and value added processes for ground floor column
No.
1
2
3
Process
Steel work column part A, C.
Form work column part A,C
Check column before casting
for part C
46
Step
number
1
2
3
Step
Value
added steps
1/2
0
0
16
48
8
60
8
8
8
8
16
4
2
6
192
Duration
(hours)
1day=
8hours
24
96
12

Table 4.10 Non-value added and value added processes for ground floor column (cont.)
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Cast column part C.
Check column part A
Cast column part A
Remove form work part A, C
Steel work for column part B
Form work column part B
Check column part B
Cast column part B
Remove form work part B
Remove 7 column(error work
Steel work part B for the seven column
Form work part B for the seven column
Checking the column
Cast column
Remove form work
Total
Percentage of value added steps
4.4.9 Ground floor
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
18
10%
Table (4.11) shows seven processes where the number of value added steps is 3 out of 7
steps (43 %) and the total duration in the daily report is 64 hours.
No.
1
2
3
4
5
6
7
1/3
0
1/3
0
1/2
0
0
1/3
0
0
0
0
0
0
0
2
Table 4.11 Non-value added and value added processes for ground floor
Process
Mechanic work for part A,B,C
Preparation work for part A,B
Steel work for part A,B
Cast ground floor for part A,B
Preparation work for part C
Steel work for part C
Cast ground floor for part C
Total
Percentage of value added steps
47
Step
number
1
2
3
4
5
6
7
7
Steps
43%
Value
added
steps
1
0
1/2
1/2
0
1/2
1/2
3
Duration
(hours)
1days=
8hours
8
4
12
8
16
8
8
64
8
8
8
8
12
24
8
8
16
38
8
16
8
8
36
346

4.4.10 Ground floor slab
The eleven processes that represent ground floor slab are shown Table (4.12). We notice
that the number of value added steps is 4 out of 11 steps (36%) and the total duration in
the daily report is 168 hours.
Table 4.12 Non-value added and value added processes in slab
No. Process
Step
number
Step
Value added
steps
Duration
/hours
1 Form work for part A,B 1 0 48
2 Hollow cement block for part A,B 2 1/2
3 Electric work for part A,B 3 1/2
4 Mechanical work for part A,B 4 1/2
5 Cast slab ground floor part A,B 5 1/2
6 Form work fort part C 6 0 32
7 Hollow cement bloc for part C 7 1/2
8 Electric work for part C 8 1/2
9 Mechanical work for part C 9 1/2
10 Cast slab for part C 10 1/2
11 Remove form work for part A,B,C 11 0 26
Total 11 4
Percentage of value added steps 36%
4.4.11 First floor columns
Table (4.13) shows the twelve processes that constitute the first floor columns. The
number of value added steps is 2 out of 12 steps (16 %) and the total duration in the
daily report is 300 hours.
48
6
6
8
8
12
8
6
8
168

No.
Table 4.13 Non-value added processes in first floor column
Process
1 Steel work column part A,C
2 Form work column part A,C
Check column before casting
3
for part C
4 Cast column part C
5 Check column part A.
6 Cast column part A
7 Remove form work part A, C
8 Steel work for column part B
9 Form work column part B
10 Check column part B
11 Cast column part B
12 Remove form work part B
Total
Percentage of value added steps (%)
4.4.12 First floor slab
Step
number
1
2
3
4
5
6
7
8
9
10
11
12
12
Step
16%
Value added
steps
1/2
0
0
1/3
0
1/3
0
1/2
0
0
1/3
0
2
Duration/
hours
1day=
8hours
The eleven processes that represent first floor slab are shown in Table (4.14). The
number of value added steps is 4 out of 11 steps (36%) and the total duration in the
daily report is 163 hours.
No.
1
2
3
4
5
6
7
8
Table 4.14 Non-value added processes in first floor slab
Process
Step
number
Step
Value added
steps
Duration
1day=
8hour
Form work for part A,B 1
0
50
Hollow cement block for
part A,B
2 1/2
5
Electric work for part
A,B
3 1/2
4
Mechanical work for part
A,B
4 1/2
6
Cast slab ground floor
part A,B
5
1/2
6
Form work fort part C 6
0
34
Hollow cement bloc for
part C
7
1/2
16
Electric work for part C 8 1/2
4
49
32
88
8
7
12
6
12
14
72
6
6
37
300

No.
9
10
11
Table 4.14 Non-value added processes in first floor slab (cont.)
Process
Mechanical work for part
C
Cast slab for part C
Remove form work for
part A,B,C
Total
4.4.13 Ground floor building
Step
number
9
10
11
11
Step Duration
Value added
steps
36%
1/2
1/2
0
4
1day=
8hour
Table (4.15) shows eighteen processes where the number of value added steps is 5 out
of 18 steps (27%) and the total duration of the ground floor building in the daily report
is 560 hours
Percentage of value added steps
Table 4.15 Non-value added and value added processes in building for ground floor
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Steps
Building work in part A,B for first layer
Lintel form work under the windows
Cast lintel
Remove form work
Building work for part A,B in the second
layer
Lintel form work up the windows
Cast lintel for second layer
Remove form work
Building work up the window
Building work in part C for first layer
Lintel form work under the windows
cast lintel
Remove form work
Building work for part C in the second layer
Lintel form work up the windows
Cast lintel for second layer
Remove form work
Building work up the window
Total
Percentage of value added steps
50
Step
number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
18
Step
27%
Value
added
steps
1/2
0
1/2
0
1/2
0
1/2
0
1/2
1/2
0
1/2
0
1/2
0
1/2
0
1/2
5
8
6
24
163
Duration
(hours)
56
24
6
16
72
24
8
8
48
8
48
8
80
56
16
76
24
38
560

4.4.14 First floor building
Table (4.16) shows the eighteen processes that represent first floor building. The
number of value added steps is 5 out of 18 steps (27%) and the total duration in the
daily report is 550 hours.
Table 4.16 Non-value added and value added processes in building for first floor
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Steps
Building work in part A,B for first
layer
Lintel form work under the windows
cast lintel
Remove form work
Building work for part A,B in the
second layer
Lintel form work up the windows
Cast lintel for second layer
Remove form work
Building work up the window
Building work in part C for first layer
Lintel form work under the windows
cast lintel
Remove form work
Building work for part C in the
second layer
Lintel form work up the windows
Cast lintel for second layer
Remove form work
Building work up the window
Total
Percentage of value added steps
51
Step
number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
18
Steps
27%
Value
added
steps
1/2
0
1/2
0
1/2
0
1/2
0
1/2
1/2
0
1/2
0
1/2
0
1/2
0
1/2
5
Duration
(hours)
60
16
6
12
70
24
6
6
40
12
32
10
64
32
24
64
32
40
550

4.5 Remove or Reduce the Influence of Waste as it is Observed
Simulation has been used in each activity to measure the duration and number of steps.
Productivity data in Table (3.1) was used in the simulation model. Results are shown on
Table (4.17). The full simulation results are shown in appendix (C).
The results that were reached from mobilization and plain concrete are explained as
follows ( the other activities use the same methodology).
Figure (4.2) shows how lean is applied to mobilization and excavation activity. Firstly
by using the five why tool. The steps were reduced from seven (Table 4.3) to three steps
(Table 4.18). The seven steps are cleaning the site, demolishing existing walls, building
engineer's office, excavation work, checking soil, extended excavation and checking the
new extension excavation land.
The first three steps can be reduced to one step by coordinating cleaning, demolition
and building. These three contractors can begin work at the same time. The sixth and
seventh steps can be avoided because there is a design error.
Create 1
0
Cleaning Ex cav ation Laboratory
0 0 0
Dispose 1
0
0
Figure 4.2 Arena simulation of mobilization and excavation
Secondly, applying productivity to three processes. Cleaning lasted for 48 hours,
demolition took 32 hours and building engineer's office took 32 hours. These three
processes may start at the same time. Since the project was ready, the duration of
cleaning is supposed to be 48 hours (Table 4.3). This is considered non-value added
process.
52

Excavation data according to Table (4.2) that shows the productivity of one excavator
for 6000m 3 can be achieved in eleven days in minimum limit and in twelve days most
likely and in thirteen days maximum. This activity is considered value added process.
The data is shown in Figure (4.3).
Figure 4.3 Excavation process data
Checking soil process is done by contacting the technicians in the material lab. The time
it takes to get the results is six, eight, ten hours. This is also considered a non value
added process. The data is shown as in Figure (4.4).
Figure 4.4 Laboratory process data
53

The result by using arena simulation replication 30 times is that cleaning took 48 hours.
Non value added duration took 8.06 hours; non-value added process, excavation process
took 95.29 hours a value added process. Results are shown in appendix ( C ).
Figure (4.5) shows how lean is applied to plain concrete activity after applying lean.
The five why tool are used to identify the number of the steps in order to be reduced.
Table (4.4) show five actual steps formwork, casting, removing formwork, cast 3 m 3,
remove formwork. Table (4.19) shows that only three steps can be used by eliminating
step four and five because they were owing to a design error.
create
0
TNOW
for m w ork cast
remove form
work
Dispose 1
0
0
0
0
Figure 4.5 Applied lean to plain concrete activity
Using standardization in Table ( 4.2) using 140m 2 , five craftsmen and ten workers, the
productivity of formwork process was 3.5 days minimum, 4 days most likely and 5.5
days maximum (on eight-hours day work).
Figure(4.6) shows formwork process that is considered non-value added. Average
duration by 30 replications was 34.83 hours.
Figure 4.6 Formwork plain concrete data
54
0

The cast concrete data according to Table (3.1) is found in Figure (4.7). This process is
value added. The duration was 3.5 hours minimum, 4 hours most likely, 4.5 hours
maximum. Average duration for 30 replication was 3.97 hours.
Figure 4.7 Casting plain concrete process data
Data of formwork removal process in Table (4.2) is inputted in Figure (4.8). This is a
non-value added process. The average duration of 30 replications was 5.03 hours.
Figure 4.8 Remove formwork process data
55

Table 4.17 Simulation results
No. Activity Process
1 Mobilization
2 Plain concrete
3 Foundation
4 Column neck
5
Bitumen isolation
6 Back filling
V.A.Time 1
(hours)
N.V.A.Time 2
(hours)
Cleaning 0 48
Excavation 95.29 0
Laboratory 0 8.06
Casting 3.97 0
Form work 0 34.83
Remove form work 0 5.03
Fix steel 15.94 0
Form work 0 129.6
Casting 15.55 0
Remove form work 0 31.34
Form work 0 79.23
Casting 1.26 0
Remove form work 0 19.92
Cleaning 0 11.86
Isolation work 39.86 0
Layer 1 23.47 0
Layer 2 16.46 0
Layer 3 15.82 0
Laboratory 0 7.1
Laboratory 0 3.57
Laboratory 0 3.51
1. V.A.Time: Value Added Time: Valued added time / hours
2. N.V.A.Time: Non Value Added time/ hours.
56

Table 4.17 Simulation results (Cont.)
No. Activity Process
7 Ground Beam
8 Ground Floor
9
Column Work
10 Slab Work
11 Building Work
.
V.A.Time
(hours)
N.V.A.Time
(hours)
Form work 0 56.85
Casting 4.19
Remove form work 0 25.58
Steel work 14 0
Installation P.V.C 6.21 0
Electrical work 11.76 0
Casting 4.95 0
Mechanical work 4.95 0
Preparation 0 10.99
Steel work 27.03 0
Steel work 15.87 0
Casting 1.23 0
Form work 0 163.82
Remove form work 0 19.68
Casting 8.98 0
Electrical Work 8.69 0
Form work 0 31.58
Hollow cement 19.85 0
Remove form work 0 40.87
Steel work 32.86 0
Building 1 173.29 0
Building 2 133.24 0
Building 3 173.69 0
Form work 1 0 19.62
Form work 2 0 19.72
Cast1 5.87 0
Cast2 5.98 0
Remove 1 0 11.72
Remove2 0 11.88
57
0

Table 4.17 Simulation results (Cont.)
No. Activity Processes
12
Column Work
13 Slab Work
14 Building Work
.
V.A.Time
(hours)
N.V.A.Time
(hours)
Steel work 16.56 0
Casting 1.27 0
Form work 0 157.51
Remove form work 0 20.41
Casting 8.9 0
Electrical work 8.92 0
Form work 0 31.51
Hollow cement 20.32 0
Remove form work 0 39.37
Steel work 32.23 0
Building 1 172.75 0
Building 2 132.67 0
Building 3 172.21 0
Form work 1 0 20.07
Form work 2 0 20.15
Cast1 5.93 0
Cast2 5.99 0
Remove 1 0 12.44
Remove2 0 11.88
58

4.5.1 Mobilization and excavation
Table (4.18) shows that mobilization and excavation duration is equal to 151.35 hours.
Before applying lean tools, it was 240 hours, and the percentage of value added time
was 63%, the actual percent value added duration was 39%, and value added steps after
applying the five why tools is 33% (before applying lean tools was 14%). Step1 and 3
are merged.
No. Process
1
2
Table 4.18 Waste elimination in mobilization
Site cleaning, includes removing
trees
Demolishing the existing walling
fence, rooms and any obstructed
item existing in the proposed area
Step
number
1
Step
Value
added
steps
0
Duration
of process
(hours)
48
Duration
Value
added
time
(hours)
3
Excavation of the natural ground
to the required levels
2 1 95.29 95.29
4 Laboratory 3 0 8.06 0
Total 3 1 151.35 95.29
Percentage of value added
33% 63%
4.5.2 Plain concrete
Table (4.19) shows that plain concrete duration is equal to 41.09 hours. Before applying
lean tools, it was 63 hours, and the percent of value added time 9%, the actual duration
was 6%, and value added step percent is 33%. It was 20% before applying lean tools.
No.
Table 4.19 Waste elimination in plain concrete
Process
1 formwork concrete for
"A-B"
2 Cast plain concrete
3 Remove form work
Total
Percentage of value added
Step
number
Step
Value
added steps
0
1
2 1
3 0
3 1
33%
59
Duration
of process
(hours)
34.83
3.97
5.037
43.83
Duration
9%
0
Value
added
time
(hours)
0
3.97
0
3.97

4.5.3 Foundation
Table (4.20) shows that foundation duration is equal to 192.43 hours. Before applying
lean tools, it was 276 hours and the percent of value added time was 16%, the actual
duration was 10%, and value added step percent was 50%. It was 15% before applying
lean tools.
No.
1
2
3
4
Process
Form work foundation
concrete "A-B-C" and
steel.
fix neck column "A-B-
C"
Cast Foundation "A-B-
C"
Remove form work
Total
Percentage of value added
Table 4.20 Waste elimination in foundation
Step
number
1
2
3
Step
Value
added
step
0
1
1
4 0
4 2
50%
Duration
of
process
(hours)
129.6
15.94
15.55
31.34
192.43
Duration
Value
added
time
(hours)
0
15.94
15.55
0
31.49
16%
4.5.4 Neck column
Table (4.21) shows that neck column duration is equal to 100.41 hours, before applying
lean tools was 132 hours, and the percent of value added time 1.2%, the actual duration
was 0.8%, and value added step percent is 33 %, It was 8% before applying lean tools.
Table 4.21 Waste elimination in neck column
No.
Process
1 Form work neck column
2 cast wall concrete "A"
3 Remove form work
Total
Percentage of value added
Step
number
Step
Value
added
steps
1 0
2 1
3 0
3 1
33 %
60
Duration
/hours
Duration
79.23
1.26
19.92
100.41
1.2%
Value
Added
time /
hours
0
1.26
0
1.26

4.5.5 Isolation
Table (4.22) shows that isolation duration is equal to 39.86 hours. Before applying lean
tools was 48 hours, and the percent of value added time 100%, the actual duration was
82%, and value added step percent is 100 %. It was 50% before applying lean tools.
No.
Process
1 Isolation work
cleaning
Total
Percentage of value added
Table 4.22 Waste elimination in isolation
Step
number
1
Steps
Value added
steps
1
Duration
(hours)
39.86
Duration
Value added
time (days)
39.86
1 1 39.86 39.86
100 % 100 %
4.5.6 Back filling
Table (4.23) shows that backfilling duration is equal to 69.93 hours. Before applying
lean tools was 112 hours, and the percent of value added time 79.7%, the actual
duration was 49%, and value added step percent is 100 %. It was 50% before applying
lean tools.
No.
Table 4.23 Waste elimination for back filling
Process
1 Back filling layer1,
cleaning site
2 Laboratory
3 Back filling layer 2
4 Laboratory
5 Back filling layer 3
6 Laboratory
Total
Percentage of value added
Step
number
1
Step
Value
added
step
1
Duration
(hours)
23.47
Duration
Value
added
time
(days)
23.47
2 0 7.1 0
3 1 16.46 16.46
4 0 3.57 0
5 1 15.82 15.82
6 0 3.51 0
6 3 69.93 55.75
50% 79.7%
61

4.5.7 Ground beam
Table (4.24) shows that ground beam duration is equal to 118.59 hours. Before applying
lean tools was 192 hours, and the percent of value added time 30%, the actual duration
was 20%, and value added step percent is 67 %. It was 50% before applying lean tools.
No.
1
2
3
4
Table 4.24 Waste elimination for ground beam
Process
Form work for ground
beam "A-B-C"
Steel work
Install and test
UPVC+ earth electric
Earth electric work
5 Caste ground beam
6 Remove form work
Total
Percentage of value added
4.5.8 Column ground floor
Step
number
1
2
3
4
5
6
6
Step
67%
Value
added step
0
1
1
1
1
0
4
Duration
(hours)
56.85
14
6.21
11.76
Duration
Value
added
time
0
14
6.21
11.76
4.19 4.19
25.58 0
118.59 36.16
30%
Table (4.23) shows that column ground floor duration is equal to 200.6 hours. Before
applying lean tools was 346 hours, and the percent of value added time 8.5%, the actual
duration was 4.7%, and value added step percent is 50 %. It was 10% before applying
lean tools.
No.
Table 4.25 Waste elimination for ground floor column
Process
1 Steel work
2 Form work
3 Cast column
4 Remove form work
Total
Percentage of value added
Step
numb
er
1
2
3
4
4
Step
50%
62
Value
creatio
n step
1
0
1
0
2
Duration
(hours)
15.87
163.82
1.23
19.68
200.6
Duration
Value
added
time (hours)
15.87
0
1.23
0
17.1
8.5%

4.5.9 Ground floor
Table (4.26) shows that ground floor duration is equal to 47.56 hours. Before applying
lean tools was 64 hours, and the percent of value added time 77%, the actual duration
was 55%, and value added step percent is 75 %. It was 57% before applying lean tools.
No.
Table 4.26 Waste elimination for ground floor
Process
1 Preparation work
2 Steel work
3 Mechanical work
4 Cast concrete
Total
Percentage of value
added
Step
number
1
2
3
4
4
Step
75%
Value
added
step
0
1
1
1
3
Duration
10.99
27.03
4.95
4.59
47.56
Duration
77%
Value
added
time
0
27.03
4.95
4.59
36.57
4.5.10 Ground floor slab
Table (4.27) shows that slab ground floor duration is equal to 142.83 hours. Before
applying lean tools was 168 hours, and the percent of value added time 49% the actual
duration was 41%, and value added step percent is 67 %. It was 44% before applying
lean tools.
No.
Table 4.27 Waste elimination for ground floor slab
Process
1 Form work
2 Hollow cement block
3 Steel work
Electric + mechanic
4
work
5 Cast concrete
6 Remove form work
Total
Percentage of value added
Step
number
1
2
3
4
5
6
6
63
Step
67%
Value
added step
0
1
1
1
1
0
4
Duration
31.58
19.85
32.86
8.69
Duration
Value
added
time
0
19.85
32.86
8.69
8.98 8.98
40.87 0
142.83 70.38
49%

4.5.11 Column first floor
Table (4.28) shows that column first floor duration is equal to 195.75 hours. Before
applying lean tools was 346 hours, and the percent of value added time 9%, the actual
duration was 4.7%, and value added step percent is 50 %.It was 10 % before applying
lean tools.
No.
Table 4.28 Waste elimination in first floor column
Process
1 Steel work
2 Form work column
3 Cast column
4 Remove form work
Total
Percentage of value added
Step
number
1
2
3
4
4
Step
Value
added step
Duration
(hours)
Duration
1 16.56
- 157.51
1 1.27
- 20.41
2 195.75
50% 9%
Value
added
time (hours)
16.56
0
1.27
0
17.83
4.5.12 First floor slab
Table (4.29) shows that slab first floor duration is equal to 140.53 hours. Before
applying lean tools was 168 hours, and the percent of value added time 50%, the actual
duration was 44%, and value added step percent is 67 %. It was 41% before applying
lean tools.
No.
Table 4.29 Waste elimination for first floor slab
Process
1 Form work
2 Hollow cement block
3 Steel work
4 Electric, mechanic
work
5 Cast concrete
6 Remove form work
Total
Percentage of value added
Step
number
1
2
3
4
5
6
6
64
Step
Value
added step
67%
0
1
1
1
1
0
4
Duration
31.51
20.32
32.23
8.92
8.9
39.37
140.53
Duration
Value
Added
Time (hrs)
0
20.32
32.23
8.92
8.9
0
70.37
50%

4.5.13 Building in ground floor
Table (4.30) shows that building ground floor duration is equal to 554.91 hours. Before
applying lean tools was 560 hours, and the percent of value added time 88%, the actual
duration was 87%, and value added step percent was 55 %. It was 26% before applying
lean tools.
Table 4.30 Waste elimination for ground floor building
Step
Duration
No. Process Step
number
Value
added
step
Duration
(hours)
Value
Added
Time (hrs)
1 Building work
1 1 173.29 173.29
2 Form work
2 0 19.62 0
3 Cast lintel
3 1
5.87 5.87
4 Remove form work 4 0 11.72 0
5 building work 2
5 1 133.24 133.24
6 Lintel work form
work 1
6 - 19.62 0
7 Cast lintel
7 1 5.98 5.98
8 Remove form work 8 - 11.88 0
9 Building work 3 9 1 173.69 173.69
Total
9 5 554.91 492.07
Percentage of value added
55%
88%
4.5.14 Building in first floor
Table (4.31) shows that building first floor duration is equal to 553.37 hours. Before
applying lean tools was 560 hours, and the percent of value added time 88%, the actual
duration was 87%, and value added step percent is 55 %. It was 26% before applying
lean tools.
Table 4.31 Waste elimination for first floor building
Step
Duration
No. Process
Step
numb
er
Value
added
step
Duration
(hours)
Value
Added
Time (hrs)
1 Building work
1 1 172.75 172.75
2 Form work
2 0 20.07 0
3 Cast lintel
3 1 5.93 5.93
4 Remove form work 4 0 11.72 0
5 Building work 2 5 1 132.67 132.67
6 Lintel work form work 6 0 20.1 0
7 Cast lintel
7 1 5.99 5.99
8 Remove form work 8 0 11.88 0
9 Building work 3 9 1 172.21 172.21
Total
9 5 553.37 489.55
Percentage of value added 55%
88%
65

4.6 Identify the Cause of Waste
Table (4.32) shows the difference between activity before and after applying lean in
order to demonstrate the effect of lean on the activity and also to identify the activities
that can be improved. The difference column (PVAT) is in descending order.
Table 4.32 Difference between activity before and after lean application
No. Activity
Before applying
lean
PVAS 3
(%)
PVAT 4
%
After applying
lean
PVAS
(%)
PVAT
%
Difference
PVAS
(%)
PVAT
%
1 Back filling 50 49 50 79.7 0 30.7
2 Mobilization 14 39 33 63 19 24
3 Ground floor 57 57 75 77 18 20
4 Isolation 50 82 100 100 50 18
5 Ground beam 43 18.8 67 30 24 11.2
6
7
Slab work in
first floor
Slab work
ground floor
36 41 67 50 31 9
36 41 67 49 31 8
8 Foundation 15 11 50 16 35 5
9
Column first
floor
10 Column
ground floor
11 Plain
concrete
Building
12 work in
13
ground floor
Building
work in first
Floor
10 5 50 9 40 4
10 4.9 50 8.5 40 3.6
20 6 33 9 13 3
26 87 55 88 29 1
26 87 55 88 29 1
14 Neck column 8 1 33 1 25 0
3. Percent value added time.
4. Percent value added steps.
66

Figure (4.9) is divided into four quarters.
In the first quarter, little improvement in value added steps which produces high
improvement in value added time in the backfilling, ground floor, mobilization and
excavation activities. The backfilling activity was 0% in the value added steps and
30.7% in value added time. This happened by avoiding the delay of the work of the
excavator which stopped for a certain period of time. Stopping was due to an error in
the design. The production of the excavator was not satisfactory because the foremen
were absent. The mobilization and excavator activities increase by 19% in value added
steps and 26% in value added time by avoiding the unclear design. Ground floor activity
increased by 18% in value added steps and 20% in value added time by increasing the
management experience.
In the second quarter, a slight improvement in value added steps led to the same
improvement in value added time. The ground beam activity raised by 17% in value
added steps and 11% in value added time. The plain concrete activity increased by 3%
in value added time because the percentage of non value added activity of the formwork
and removing it, are less than value added activity.
In the third quarter, the big improvement in value added steps gave only a little
improvement in the value added time. The value added steps in the slab activity has
raised by 23% and the value added time raised by 8%. The value added steps for the
columns activity raised by 40% and value added time 3.6%. The number of the steps of
the neck columns improved by 25% and the value added time did not improve. The
number of steps of building activity improved by 29% and value added time by 1%.
This all happened because the non value added processes (form work and removing it)
had a big time value inside the activity.
In the fourth quarter, a big improvement in the value steps produced big improvement in
the value added time. The number of steps in the isolation activity of the value added
steps rose by 50% that also rose the value added time by 18%. These rises happened
because cleaning process was done after removing the formwork. It was done during the
work of the contractor because of the lack of workers and the cleaning material.
67

Percent of value adding time
35%
30%
25%
20%
15%
10%
5%
0%
2
1
0% 10% 20% 30% 40% 50% 60%
Percent of value adding steps
Figure 4.9 Comparing value added steps to value added time
Regarding the causes of delays of activities, using the five why tools showed the
following results:
• The failure due to design error was 30.7%.
• The failure due to work error was 24%.
• The failure due to lack of experienced management was 20%.
4
• The failure due to lack of resources was 18% due to lack of permanent
resources.
• The failure due to lack of material formwork was 8% because the contractor
had to divide the project into many stage because of lack of the formwork. The
solution is to save enough formwork. Figure (4.10) shows the percentage of
the causes of a failure as in the diagram.
68
3

Percent of non value added
process
35
30
25
20
15
10
5
0
Design error Work error Lack of
experience
Lack of number
of ressources
Cause of non value added process
Figure 4.10 Cause of failure
4.7 Finding the Largest Non-Value Added Process
Lack of
material
The eight points that were mentioned in the methodology (4.3) were applied using arena
simulation in order to find the biggest non value added process. The whole non value
added process is shown in Table (4.33) by putting “0” non value added process in turn
and calculating the time period in the end of the project (run the simulation Figure
(4.11)).
TNOW
Create 2
MOBILIZATION
0
PLAIN CONCRETE FOUNDATION NICK COLUMN ISOLATION DEMOLITION
GROUND BEAM COLUMN1 GROUND FLOOR Slab work
building work1 building work2 Dispose 2
Figure 4.11 Simulation model
69
0
Column2 SLAB2

Table 4.33 Total project duration
No. Process
Non value added Time
=0
1
Mobilization and
excavation
Site cleaning
Laboratory
0
0
2
Plain concrete
Form work concrete
Remove form work
0
0
3
Foundation
Form work concrete
Remove form work
0
0
4
Neck column
Form work concrete
Remove form work
0
0
5 Isolation Cleaning 0
6 Back filling
Laboratory of layer1
Laboratory of layer2
0
0
Laboratory of layer3 0
7 Ground beam
Form work concrete
Remove form work
0
0
8 Column ground floor
Form work concrete
Remove form work
0
0
9. Ground floor Preparation work 0
10 Slab work ground floor
Form work concrete
Remove form work
0
0
11 Column first floor
Form work concrete
Remove form work
0
0
12 Slab work first floor
Form work concrete
Remove form work
0
0
Form work concrete 0
13
Building work in ground
floor
Remove form work
Form work concrete
0
0
Remove form work 0
Form work concrete 0
14 Building work in first floor
Remove form work
Form work concrete
0
0
Remove form work 0
70
Total
duration
2951.3
2991.3
2964.5
2994.3
2869.7
2968
2920.1
2979.4
2992.2
2995.8
2995.8
2942.5
2973.8
2835.5
2979.7
2988.3
2967.8
2958.5
2841.8
2978.9
2967.8
2960
2979.7
2987.6
2979.6
2987.5
2979.3
2986.9
2979.2
2987.5
2951.3

Then the candidates have been sorted out in order of their significance duration based
on simulation results. This enables the improvement process to focus on those activities
that have the greatest impact on model outputs (Table 4.34).
Table 4.34 Activities in a descending order based on duration
No. Activity Non- value added
Total
duration(hours)
1 Column ground floor Form work concrete 2835.5
2 Column first floor Form work concrete 2841.8
3 Foundation Form work concrete 2869.7
4 Neck column Form work concrete 2920.1
5 Ground beam Form work concrete 2942.5
6 Mobilization and Site cleaning 2951.3
7 Slab work ground floor Remove form work 2958.5
8 slab work first floor Remove form work 2960
9 Plain concrete Form work concrete 2964.5
10 Slab work ground floor Form work concrete 2967.8
11 slab work first floor Form work concrete 2967.8
12 Foundation Remove form work 2968
13 Ground beam Remove form work 2973.8
14 Column first floor Remove form work 2978.9
15 Building work in first floor Form work concrete 2979.2
16 Building work in first floor Form work concrete 2979.3
17 Neck column Remove form work 2979.4
18 Building work in ground Form work concrete 2979.6
19 Column ground floor Remove form work 2979.7
20 Building work in ground Form Work Concrete 2979.7
21 Building work in first floor Remove form work 2986.9
22 Building work in ground Remove form work 2987.5
23 Building work in first floor Remove form work 2987.5
24 Building work in ground Remove form work 2987.6
25 Ground floor Preparation work 2988.3
26 Mobilization and Laboratory 2991.3
27 Back filling Laboratory of layer1 2992.2
28 Plain concrete Remove form work 2994.3
29 Back filling Laboratory of layer2 2995.8
30 Back filling Laboratory of layer3 2995.8
71

Then, the processes with the greatest impact on the project duration are identified and
shown in Table (4.35).
Calculated of the value added percent is as follows:
V.A. Percent=Value added / Total duration
Value added according the appendix (c)=1906.15 hours
V.A.Percent of the form work the ground floor column = 1906.15 / 2835.5 = 67%.
V.A.Percent of the form work the first floor column = 1906.15 / 2841.8 = 67%.
V.A.Percent of the form work the foundation = 1906.15 / 2869.7 = 66%.
No. Process
Table 4.35 Greatest duration of waste in activity
Non value added
Total
duration
(hours)
V.A
Percent
(%)
1 Ground floor column Form work concrete 2835.5 67%
2 First floor column Form work concrete 2841.8 67%
Foundation Form work concrete
3 2869.7 66%
In case of putting “0” for the three process, the results are shown in Table (4.36).The
full simulation result is shown in appendix (D).
Calculated of the value added percent is as follows:
Value added percent = 1906.15 / 2563.05 = 74%
No.
1
Table 4.36 Project duration without the most wasting activity
Process
Non- value
added process
Foundation Form work Concrete
Ground floor column Form work Concrete
First floor column Form work Concrete
72
Total
duration
(hours)
2563.05
V.A
Percent
(%)
74%

Finally, buffers are introduced to balance the processes duration.
Figure (4.12) shows that duration of the foundation formwork process is 129.6 hours.
This is far from the other processes (shown as number eight). Ground floor columns
formwork process duration are 163.82. First floor columns formwork process duration
was 157.51 hours. These are longer than the other processes (shown as number 34, 53).
The duration of the building processes took 173.29, 133.2, 173.69, 172.75, 132.67,
172.21 hours. These numbers correspond to 42, 43, 44, 61, 62, 63. These duration are
larger than those in the other processes.
Duration (hours)
200
180
160
140
120
100
80
60
40
20
0
Non value added process Value added process
1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58 61 64 67
Process
Figure (4.12) Duration variability before introducing buffers and after applying lean
tools
Table (4.37) shows the balance improvement into the process by decreasing the duration
of processes. Foundation formwork process duration decreased from 129.6 hours to
42.6 hours by increasing the number of resources from 9 to 27 workers shown as
number eight in Figure (4.13). The duration of excavation process decreased from 95.29
to 45 hours by using 2 excavators shown as number three. The duration of the ground
floor columns formwork decreased from 163.82 hours to 56.49 hours by increasing the
number of workers to12 workers shown as number 34. The first floor columns
formwork duration decreased from 157.51 hours to 56.49 hours by increasing the
73

number of workers to 12 workers shown as number 53. The ground floor building
duration decreased from 173.29, 133.24, 173.96 hours to 65.9, 66.07, 66.37 hours by
increasing the number of workers to 13, 10, 13 workers shown as number 42, 43, 44.
The first floor building duration decreased from 172.75, 132.67, 172.21 hours to 65.9,
66.07, 66.37 hours by increasing the number of workers to 13, 10, 13 workers shown as
number 61, 62, 63.
The result of introducing buffer is that the non-value added time decreased by 55%
(from 1906.15 hours to 846.5 hours).
Activity Process
Mobil.
Plain
Table 4.37 Balancing the process
Before introducing buffers After introducing buffers
New
resources
number
VA
hours
NVA
hours
New
resources
number
New
V.A.
New
NVA
Check - 0 8.06 - 0 8.06
Cleaning - 0 48 - 0 48
Excavation
concret. Remove
Found.
Neck
1
Excavator
95.29 0
2
Excavator
45 0
Casting 5 3.97 0 5 3.97 0
Form Work 5 0 34.83 5 0 34.83
form
5 0 5.03 5 0 5.03
Fix steel 9 15.94 0 9 15.94 0
Form work 9 0 129.6 27 0 42.6
Casting 9 15.55 0 9 15.5 0
Remove
Formwork
Column Remove
formwork
9 0 31.34 9 0 31.3
Formwork 8 0 79.23 14 0 67.29
Casting 8 1.26 0 8 1.26 0
8 0 19.92 8 0 19.9
74

Activity Process
Isolation Isolation
Backfilling
Ground
beam
Table 4.37 Balancing the process (cont.)
Before introducing buffers
NRN
VA
hours
NVA
hours
After introducing
NRN
buffers
New
V.A.
New
NVA
Cleaning 2 0 11.86 2 0 11.8
work
Layer 1
Layer 2
Layer 3
2 39.86 0 2
2
Excavato
r
2
Excavat.
2
Excavat.
23.47 0
16.46 0
15.82 0
2
Excav.
2
Excav.
2
Excav.
39.8
6
23.4
7
16.4
6
15.8
2
Laboratory 1 - 0 7.1 - 0 7.1
Laboratory 2 - 0 3.57 - 0 3.57
Laboratory 3 - 0 3.51 - 0 3.51
Form Work 8 0 56.85 16 0 29.85
Casting 8 4.19 0 8 4.19 0
Remove form 8 0 25.58 8 0 25.58
Steel work 8 14 0 8 14 0
Install. PVC 8 6.21 0 8 6.21 0
11.7
Electrical 8 11.76 0 8 0
6
75
0
0
0
0

Activity Process
Ground
floor
Column
work
Slab
work
ground
floor
Building
ground
floor
Table 4.37 Balancing the process (cont.)
Before introducing buffers After introducing buffers
NRN
VA
hours
NVA
hours
NRN
New
V.A.
Casting 5 4.95 0 5 4.95 0
Mechanical
work
New
NVA
5 4.95 0 5 4.95 0
Preparation 5 0 10.99 5 0 10.99
Steel work 5 27.03 0 5 27.03 0
Steel work 4 15.87 0 4 15.87 0
Casting 4 1.23 0 4 1.23 0
Form work 4 0 163.82 12 0 56.49
Remove form
Work
4 0 19.68 4 0 19.68
Casting 9 8.98 0 9 8.98 0
Electrical
work
9 8.69 0 9 8.69 0
Form work 9 0 31.58 9 0 31.58
Hollow
cement
Remove form
work
9 19.85 0 9 19.85 0
9 0 40.87 11 0 32.47
Steel work 9 32.86 0 9 32.86 0
Building 1 5 173.29 0 13 65.9 0
Building 2 5 133.24 0 10 66.07 0
Building 3 5 173.69 0 13 66.37 0
Form work 1 5 0 19.62 5 0 19.62
Form work 2 5 0 19.72 5 0 19.72
Cast1 5 5.87 0 5 5.87 0
Cast2 5 5.98 0 5 5.98 0
Remove 1 5 0 11.72 5 0 11.72
Remove2 5 0 11.88 5 0 11.88
76

Activity Process
Column
work first
floor
.
Slab work
first floor
Building
work
first floor
Table 4.37 Balancing process (Cont.)
Before introducing buffers After introducing buffers
NRN
VA
hours
NVA
hours
NRN
New
V.A.
Steel work 5 16.56 0 5 16.56 0
Casting 5 1.27 0 5 1.27 0
New
NVA
Form work 5 0 157.51 12 0 56.49
Remove
form
5 0 20.41 5 0 20.41
Casting 9 8.9 0 9 8.9 0
Electrical
work
9 8.92 0 9 8.92 0
Form work 9 0 31.51 9 0 31.51
Hollow
cement
Remove
form work
9 20.32 0 9 20.32 0
9 0 39.37 11 0 32.47
Steel work 9 32.23 0 9 32.23 0
Building 1 5 172.75 0 13 65.9 0
Building 2 5 132.67 0 10 66.07 0
Building 3 5 172.21 0 13 66.37 0
Form work 1 5 0 20.07 5 0 20.07
Form work 2 5 0 20.15 5 0 20.15
Cast1 5 5.93 0 5 5.93 0
Cast2 5 5.99 0 5 5.99 0
Remove 1 5 0 12.44 5 0 12.44
Remove2 5 0 11.88 5 0 11.88
77

Actual project duration was 6000 hours.
Actual non-value added duration of total process was 4892.17 hours.
Total duration, before introducing buffer, was 3013.98 hours.
Value added duration of total process before introducing buffer was1906.15.
Total duration after introducing buffer was 1503.43 hours.
Non value added duration of total process after introducing buffer was 846.5 hours.
80
70
60
50
40
30
20
10
0
Non value added processes Value added processes
1 5 9 13 17 21 25 29 33 37 41 45 49 53 57 61 65 69
Process
Figure (4.13) Duration variability after Introducing buffers
The contracting time duration was 2920 hours. After applying lean tools the total
duration was 1503.15.
Table (4.38) shows the cycle time decrease from 6000 hours to 1503.43 hours
(reduction by 75%).
Table 4.38 Cycle time compared
Activity
Total
duration
Actual
duration
hours
Application
of lean tools
Cycle time after
introducing buffer
Duration (hours) % Duration(hours) %
6000 3013.98 50%
78
1503.43 75%

4.8 Application of Lean Construction for Future Construction Project
In order to apply lean construction on future projects, we have to apply the following
points:
1. To improve master schedule of the project by using standardization tool
2. To hold a weekly meeting and to determine percent plan complete (PPC) of
the process of the assignment by evaluation of the steps. Advancement of the
project can be measured every 4 weeks or 6 weeks according to the size of
the project. The average must be more than 80%. Later on the change of
average may become very simple.
3. To apply the 5 why tool to identify the main reasons of failure.
4. Correcting and avoiding any previous failure in the following week.
5. To measure the average of the percent plan complete in each 4 weeks, the
weekly meeting will be good if the percent plan complete is more than 80%.
6. To identify, remove or reduce the non-value added process
7. To make a continuous improvement.
Applying the above points to the mobilization and excavation activity described in
project studied: cleaning work, cutting trees, demolition existing wall in the site,
building an engineering office, excavation work first layer, excavation second layer, and
excavation third layer. Table 4.39 shows the process completed and the process
assigned in the master schedule of a real project. In the 1 st , 2 nd , 3 rd week there are two
assigned process (cleaning, cutting trees) and only one was completed. In the 4 th and 5 th
week there are three assigned (cleaning, cutting trees, demolition) and only two
processes were completed. In the 6 th and 7 th week there are four assigned and only
three processes were completed. In the 8 th and 9 th week, there are five assigned and only
four processes were completed. In the 10 th week, there are 6 assigned and only 5
processes were completed. In the 11 th week there are 7 assigned and only 5 processes
were completed.
79

Date
Process
Assigned
Process
Completed
Table 4.39 Process assigned and process completed
1 st
Week
2 nd
Week
3 rd
Week
4 th
Week
5 th
Week
6 th
W.
7 th
W.
8 th
W.
9 th
W.
10 th
2 2 2 3 3 4 4 5 5 6 7
1 1 1 2 2 3 3 4 4 5 5
Figure (4.14) shows the real percentage plan complete of each week.
PPC=(Number of processes completed / Number of processes assigned) X 100
In the 1 st , 2 nd , 3 rd weeks, the PPC=1/2 x100=50%. In the 4 th week, 5 th week the PPC =
2/3 x100 = 66%, in the 6 th week, 7 th week the PPC= 3/4x100= 75%. %. In the 4 th week,
5 th week the PPC = 2/3 x 100 = 66%, in the 8 th week, 9 th week the PPC= 4/5 x 100
=80%. In the 10 th week the PPC = 80%, in the 11 th week the PPC= 70%. This needs to
determine the main reasons of failure.
Using the five why tool, the cause of failure is the lack of experienced management and
the lack of number of resources.
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
Week 1 Week
2
Week
3
Week
4
Week
5
Week
6
Week
7
Week
8
Week
9
Week
10
Figure 4.14 Actual percent plan complete of each week (PPC)
80
W.
Week
11
11 th
W.

Figure (4.15) shows the average of percent plan complete is smaller than 80% which
requires finding out failure reasons in each week. By the application of the five why
tools and the 10 points described in part (3.3).
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
w eekly percent plan complete Average percent plan complete
Week 1 Week
2
Week
3
Week
4
Week
5
Week
6
Week
7
Week
8
Week
9
Week
10
Figure 4.15 Average percent plan complete of each four week
81
Week
11

5.1 Conclusion
Chapter Five
Conclusion and Recommendations
This study of Lean Construction Practices in the Gaza Strip shows the influence of
applying the lean construction. This study was conducted by identifying criteria of lean
construction and applying standardization tools, 5 why tools, 10 point to achieve the
lean principle in reducing the activity steps and duration by eliminating the non value
added process in the activity by using the arena simulation. The following consequences
have been reached:
1. Value added time increased from 49% to 63% as a result of applying lean tools.
2. The used lean tools decrease the cycle time from 6000 hours to 1503.43 hours
(decreased by 75%).
3. The value added can be enhanced to 74% by improving the form work material in
foundation (using prefabricated) and column activities ( steel form work).
4. The number of steps decreased from 161 to 69 (a reduced by 57%).
5. Non -value added duration of total process was 4892.17 hours (81%) ; it decreased
to 846.5 hours ( 14% decrease).
6. Lean construction through standardization tools reduces the variability of the
process, example the excavation work for one hour (57m 3 , 62m 3 , 68m 3 ).
7. The rate of no value added process related to the design error was 30.7%. This has
been considered the biggest value of the no value added in the process since it
happens during the stage of design, therefore, we must apply the lean in the design
to avoid waste during the construction.
8. The percentage of the no value added in the process due the above mentioned
reasons were as follow: Rework 24% lack of experience management 20%, lack of
number of resources 18%, lack of material 8%. This requires training workers.
Engineers, other managers, supervisors should begin suitable courses in
management. It is favorable to work with a permanent technical staff in the
company. Efficient resources, sufficient materials should be provided and saved for
the project.
82

5.2 Recommendations
In order to apply lean construction tools and achieve its benefits successfully, the
following recommendations should be considered:
1. Using standardization tool in companies.
2. Training the workers in the company in order to reach the needed productivity
which has big effects on the improvement of work.
3. Using the 5 why tools to identify the errors and their causes to avoid them and not
looking for the mistaken people.
4. Focusing on this study as a first step to use the lean in construction projects.
5. Applying the methodology used in the current study to all companies in the Gaza
Strip.
6. Improving the master schedule of the project by standardization tools and measuring
the percent plan complete for each process to deal with errors weekly.
7. Process evaluation and project progress should be measured every 4 weeks as
mentioned in the last planner tools.
8. The percent plan complete average of lean project must be more than 80%.
9. After proving the potential application, lean studies should focus on obstacles of
lean implementation.
83

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88

Appendix A Daily Report.
Appendix B Arena Simulation.
List of Appendices
Appendix C Simulation result of the project before applying eight points and after
applying lean tools.
Appendix D Simulation Result after applying "0" for three biggest non-value added
processes of the project during applying eight points.
89

Appendices (A)
Daily report
Date Activity
26/06/2003 Site cleaning, includes removing trees
27/06/2003 Site cleaning, includes removing trees
28/06/2003
29/06/2003
30/06/2003
Site cleaning, includes removing trees, demolishing the existing
walling fence, rooms and any obstructed item existing in the proposed
area
Site cleaning, includes removing trees, demolishing the existing
walling fence, rooms and any obstructed item existing in the proposed
area and building engineer office
Site cleaning, includes removing trees, demolishing the existing
walling fence, rooms and any obstructed item and existing in the
proposed area and building engineer office
01/07/2003
Site cleaning, includes removing trees, demolishing the existing
walling fence, rooms and any obstructed item and existing in the
proposed area and building engineer office.
02/07/2003 Building engineer office
03/07/2003 Building engineer office
04/07/2003 Building engineer office
05/07/2003 Building engineer office
06/07/2003 Excavation of the natural ground to the required levels
07/07/2003 Excavation of the natural ground to the required levels
08/07/2003 Excavation of the natural ground to the required levels
09/07/2003 Excavation of the natural ground to the required levels
10/07/2003 Excavation of the natural ground to the required levels
12/07/2003 Excavation of the natural ground to the required levels
13/07/2003 Excavation of the natural ground to the required levels
14/07/2003 Excavation of the natural ground to the required levels
15/07/2003 Excavation of the natural ground to the required levels
16/07/2003 Excavation of the natural ground to the required levels
17/07/2003 Excavation of the natural ground to the required levels
18/07/2003 Excavation of the natural ground to the required levels
20/07/2003 Laboratory
21/07/2003 Expand the excavation
22/07/2003 Expand the excavation
23/07/2003 Laboratory
A1

Date
24/07/2003
26/07/2003
27/07/2003
28/07/2003
29/07/2003
30/07/2003
31/07/2003
02/08/2003
03/08/2003
04/08/2003
05/08/2003
06/08/2003
07/08/2003
09/08/2003
10/08/2003
11/08/2003
12/08/2003
13/08/2003
14/08/2003
16/08/2003
17/08/2003
18/08/2003
19/08/2003
20/08/2003
21/08/2003
23/08/2003
24/08/2003
25/08/2003
26/08/2003
27/08/2003
28/08/2003
30/08/2003
31/08/2003
01/09/2003
02/09/2003
03/09/2003
Activity
Cheblona work
Cheblona work and Form work concrete
Cheblona work and Form work concrete
Cast in site 10cm thick plain concrete (B200) for "A-B"
Cast in site 10cm thick plain concrete (B200) for "C"
Form work foundation concrete "c" and steel work
Form work foundation concrete "c", steel and cast 3M3 plain
concrete
Form work foundation concrete "c" and steel
Form work foundation concrete "A-B-C"
Form work foundation concrete "A-B-C "and steel
Form work foundation concrete "A-B" steel work and fix neck
column "A-B"
Form work foundation concrete "A-B-C" and steel
Fix neck column "B" and cast foundation "A-B"
Remove form work part "A", form work for foundation "c-b", steel
work and neck column
Steel work for foundation part "B", fix steel neck column and cast
foundation part
Form work foundation concrete "A "and steel work.
Cast ready mix concrete (B300) for reinforced concrete ground
beams "B".
Remove form work and steel work and cleaning
Remove and reinforced concrete basement walls form work
Form work neck column and wall concrete
Form work neck column A-B and wall concrete and adjust of column
Form work neck column A-B and wall concrete and adjust of column
Form work wall concrete and cast wall concrete "A" and form work
"B"
Remove form work "A" neck column, form work wall concrete and
neck column "B"
Cast neck column "B", form work "B" wall and neck column
Form work neck column "A,B" and remove form work wall
Form work part "B-C" and cast neck column part B
Cast A-C
Remove form work and cleaning foundation.
Isolation work and Cleaning site
Form work for wall and neck column part "c", isolation work and
Cleaning site
Form work for wall and neck column , isolation work and cleaning
site
Isolation work and cleaning site
Back filling and cleaning site
Back filling , laboratory and cleaning site
Back filling 25cm , laboratory and cleaning site
A2

04/09/2003
06/09/2003
07/09/2003
08/09/2003
09/09/2003
10/09/2003
11/09/2003
13/09/2003
14/09/2003
15/09/2003
16/09/2003
17/09/2003
18/09/2003
20/09/2003
21/09/2003
22/09/2003
23/09/2003
24/09/2003
25/09/2003
26/09/2003
27/09/2003
28/09/2003
29/09/2003
30/09/2003
01/10/2003
02/10/2003
04/10/2003
08/10/2003
09/10/2003
11/10/2003
12/10/2003
13/10/2003
14/10/2003
15/10/2003
16/10/2003
18/10/2003
19/10/2003
20/10/2003
21/10/2003
22/10/2003
23/10/2003
25/10/2003
26/10/2003
27/10/2003
Back filling 25 cm , laboratory and cleaning site
Form work for 5 foundation part "c", back filling work and steel work
Form work for 5 foundation, back filling second layer25 cm
Form work for 5 foundation part "c", back filling , steel work and
laboratory
Back filling 25 cm
Form work for wall part "c" and Back filling 25 cm
Form work for wall, neck column part "c" and back filling 25 cm
Form work neck column part "c" and back filling part "A-B"
Cast neck column part "c" and back filling
Remove form work neck column and Back filling
Back filling work 25 cm
Back filling work 25 cm, form work for ground beam and isolation
work
Back filling work 25 cm and form work for ground beam
Form work for ground beam "A-B-C"
Form work for ground beam "A-B-C"
Form work for ground beam " B "
Form work for ground beam " B "
Form work for ground beam " B "
Form work for ground beam " B "
Form work for ground beam " B "
Form work for ground beam " B "
Form work for ground beam "A-B-C"
Steel work , excavation under ground beam part "B"
Steel work "A-B"
Form work ground beam "A-C", steel work for part "B", Supply,
install and test UPVC and earth electric..
form work for ground beam "A-B-C" , sanitary work and earth
electric
Form work ground beam "B" and earth electric
Caste ground part "C"
Caste ground part "A"
Remove form work "A", Form work wall and column "c"
Remove form work "A", Form work wall and column "c", steel work
ground beam "c"
Form work G. beam, Form work column "c" and mechanical work
Form work G.beam , Wall "B", Steel work "c", Isolation work
Form work G. beam, Steel work column, isolation work
Form work wall , Column" ABC"
Form work wall and Column "ABC"
Cast G. Beam "B", form work wall and column "AC"
Remove form wall"B",Form work "AC"
Remove form wall"B"and form work "AC"
Remove form wall"B"and form work "AC"
Form work "ABC"
Form work "ABC"
Finishing work and isolation
Isolation work and cleaning
A3

28/10/2003
30/10/2003
01/11/2003
02/11/2003
03/11/2003
04/11/2003
05/11/2003
06/11/2003
08/11/2003
09/11/2003
10/11/2003
11/11/2003
12/11/2003
13/11/2003
15/11/2003
16/11/2003
17/11/2003
18/11/2003
19/11/2003
20/11/2003
22/11/2003
23/11/2003
24/11/2003
29/11/2003
30/11/2003
01/12/2003
04/12/2003
07/12/2003
08/12/2003
09/12/2003
10/12/2003
11/12/2003
13/12/2003
14/12/2003
15/12/2003
16/12/2003
17/12/2003
Form work wall "c" and column "B"
Column and wall "c" and manhole work "B"
Cast column and wall "c" and manhole work "B" and cleaning work
Manhole work "BC" and remove form work "C"
Manhole work "BC" and remove form work "C"
Back filling between ground beam and mechanic work and steel
work" wall B"
Back filling between ground beam and Form work "B" and
Mechanical work
Back filling and mechanic work
Back filling and mechanic work and steel work for column A"
Steel work and Mechanic work and Column and wall "B"
Column and wall 'AB" and Mechanic work
Column and wall 'AB" and Mechanic work
Column and wall 'AB" and Mechanic work and ground floor steel
work
Cast "A" Column and wall and steel ground floor "AB" and
formwork wall and column and mechanical work
Remove form work "A" column and wall and Ground floor "B" and
Form work wall and column "B" and Mechanical work
Cast "c" ground floor and Form work column "
B" remove form work wall and column "A"
Form work column "B”, ground floor work "B" and remove form
work column "A"
Form work column, ground floor AB and Mechanical work and
ground floor slab form work
Form work column "B", ground floor work AB and mechanical work
and Slab form work "c"
Cast ground floor " AB" and Form work column "B" and Form work
slab "c"
Cast column "c", electric work "b", slab work "c" and Ground floor
"B"
Column "B", slab "c" and Ground floor "B"
Cast column "B" and Remove 7 column and Ground floor work
Steel wall and column , slab work "c" and ground floor "B"
Slab "c 'and Wall "B"
Cast ground floor 550m2 "B', slab "c" and wall work "B"
Cast wall "B"
Remove form work band steel work slab "c" and form work "A" slab
Remove form work for wall "B", slab "CA "and column work "B"
Cast column "B", Slab steel, mechanic work "CA" and Remove form
work wall "B".
Slab "AC"
Slab Work "AC" and Cast column "A"
Slab work "AC"
Slab work "AC"
Slab work "AC"
Cast slab "c"and Slab work "AC"and Wall work
Slab work "A"and Column work "c"
A4

18/12/2003
20/12/2003
21/12/2003
22/12/2003
23/12/2003
24/12/2003
25/12/2003
27/12/2003
29/12/2003
30/12/2003
31/12/2003
01/01/2004
03/01/2004
04/01/2004
06/01/2004
11/01/2004
12/01/2004
13/01/2004
14/01/2004
15/01/2004
17/01/2004
18/01/2004
19/01/2004
20/01/2004
21/01/2004
22/01/2004
24/01/2004
25/01/2004
26/01/2004
27/01/2004
28/01/2004
29/01/2004
05/02/2004
07/02/2004
08/02/2004
09/02/2004
10/02/2004
11/02/2004
12/02/2004
16/02/2004
17/02/2004
18/02/2004
19/02/2004
21/02/2004
22/02/2004
23/02/2004
24/02/2004
25/02/2004
Slab work "A"and Column work "c"
Slab work "AB"and Column work "c"
Slab work "AB"
Slab work "AB" and Column work "c"
Slab work "AB" and Column work "c"
Slab work "AB" and Column work "c"
Slab work "AB" and Column work "c"
Cast column "c" and slab "AB"
Slab work "AB"
Cast slab "A" and Work in slab "B"
Slab electric work "B"
Slab work "B"
Slab work "B"
Cast Slab work "B"1670m2andform work second floor slab "c"
Form work second floor slab "c" and Column axes "AB"
Form work second floor slab "c" and Column "AB"
Form work second floor slab "c" and Column "AB"
Form work second floor slab "c" and Column "AB"
Form work second floor slab "c" and Column "AB"
Form work second floor slab "c" and Column "AB"
Form work second floor slab "c" and Column "AB"
Column work "AB"
Form work second floor slab "c", column "AB" and Cast column "A"
Form work second floor slab "AC" and Column "B"
Cast slab "c" and Cast 16 column in part "B"
Work slab " AB' and Work column "B" and
Work slab " AB and Work column "B" and electric work
Slab "AB" and Electric slab "A" and column "B"
Cast column "B" and Slab work AB
Remove form work" B" and slab A B
Cast slab "A" and Work in slab "B".
Work in slab "B"
Work in slab "B"
Slab "B" and Column "AC
Slab "B" and Column "AC"
Cast column "C" and slab eclectic "B" and column "A"
Slab "c", cleaning, first floor column A and Slab B
Slab "c", building work and first floor column A and Slab B
Slab "c" and building work and First floor column A and Slab B
Cast column "A" and Building work and Finishing work in slab "B"
Slab "c" and Cast slab "B" and building work
Slab A C and Building work
Slab A C and Building work
Slab A, electric slab C and Building work
Slab A and Electric slab C and Lintel work
Slab A C and Building work
Slab A C and Building work
Slab A C and Building work and Column "B"
A5

26/02/2004 Slab A C and Building work and Column "B"
27/02/2004 Cast slab "C' and Slab work A and Building work
29/2/2003 Slab A and Building work and Column "B"
Stop work because there are Conflict between the contractor and the
01/03/2004 consultant.
02/03/2004
Stop work because there are Conflict between the contractor and the
consultant.
03/03/2004 Slab A and Building work AC and electric work in wall
04/03/2004 Slab A and Building work AC and electric work in wall
06/03/2004 Slab A and Building work and Column "B"
07/03/2004 Slab A and Building work and Column "B"
08/03/2004 Slab A and Building work and Column "B" and lintel work
09/03/2004 Slab A and Building work and Column "B"
10/03/2004 Slab A and Finishing Building work and Column "B"
11/03/2004 Cast column ground floor "B" and Slab electric "A" and Lintel AC
13/03/2004 Building ground floor BC and Lintel A and Column first floor "B"
Cast column ground floor "B" and check slab "A" and Lintel A and
15/03/2004 Building ground floor "B"
16/03/2004
Cast first slab "B" and cast lintel" A" and Building "B" and Electric
work and Slab first floor "B'
17/03/2004
Column first floor "B" and Slab first floor AB and building work and
Electric wall
18/03/2004
Cast column first floor "B" and slab work "B' and Lintel ground floor
"A" and Electric wall and Slab "A" and Back filling column
20/03/2004
Remove form work for column "B" and slab first floor "BC" and
Building
26/03/2003
Building ground floor "B" and lintel and slab first floor "B" and Form
work7 column "B"
27/03/2004 Building ground floor "AB" and cast "B" and slab first floor "B"
28/03/2004 Building ground floor "B" and slab first floor "B"
29/03/2004 Building ground floor "B" and slab first floor "B"
30/03/2004
Building ground floor "ACB and Slab first floor "B" and lintel
ground floor "B"
31/03/2004
Slab first floor "B" and Building first floor "c" and Lintel ground
floor "B"
01/04/2004 Slab first floor "B" and building AC and lintel "B"
02/04/2004 Slab first floor "B" and Building first floor "C"
04/04/2004 Slab first floor "B" and Lintel ground floor "B'
05/04/2004
Slab first floor "B" and lintel ground floor "B and building first floor
"A"
06/04/2004
Slab first floor "B" and lintel ground floor "B and building first floor
"B"
07/04/2004
Slab first floor "B" and lintel ground floor "B and building first floor
"A"
08/04/2004
Cast lintel "B" and lintel ground floor "C" and building up lintel "B"
and slab first floor "B"
Cast lintel "B" and lintel ground floor "C" and building up lintel "B"
10/04/2004 and s lab first floor "B" and electric floor "B" and electric ground
floor "A"
A6

11/04/2004
12/04/2004
13/04/2004
14/04/2004
15/04/2004
17/04/2004
18/04/2004
19/04/2004
20/04/2004
21/04/2004
22/04/2004
24/04/2004
25/04/2004
26/04/2004
27/04/2004
28/04/2004
29/04/2004
01/05/2004
02/05/2004
03/05/2004
04/05/2004
05/05/2004
06/05/2004
08/05/2004
09/05/2004
10/05/2004
11/05/2004
12/05/2004
13/05/2004
15/05/2004
16/05/2004
17/05/2004
18/05/2004
19/05/2004
26/05/2004
29/05/2004
21/06/2004
07/07/2004
08/07/2004
09/07/2004
11/03/2004
Cast lintel "BC" and Slab first floor "B"
Slab first floor "B" and lintel AB
Slab first floor "B"
Column first floor27"B"andBuiding "B" and lintel Ground floor A
Slab floor "B" and Building up lintel "B"
Cast lintel ground floor "B" and Electric slab work and Building
ground floor "B"
Remove form work for lintel and Electric work
Remove form work for lintel and Electric work and slab floor "B"
Slab first floor "B" and Lintel Ground floor BC
Slab first floor "B" and Lintel Ground floor ABC and building "B"
Cast Slab first floor "B" and Lintel Ground floor ABC and building
"B"
Plastering work and Start remove form work for slab first floor and
Electric work and Lintel AC
Plstering and Lintel floor "AC" and electric ground floor.
Plastering and Form work G.Floor" and Electric ground floor
Column roof and Plastering work.
Form work lintel ground floor and column roof and Plastering and
electric ground floor
Form work lintel ground floor and column roof and Plastering and
Electric G.F.
Column roof and Plastering and Electric G.F.
Column roof and Plastering and Electric G.F.
Plastering work
Stop work because of a conflict between the contractor and
consultant
Stop work because of a conflict between the contractor and
consultant
Stop work because of a conflict between the contractor and
consultant
Remove slab "B" and open window in wall and Form work
Remove slab "B" and Open window in wall and Electric work
Plastering work and Lintel and Remove form work slab
Roof slab and building work
Roof slab and Plastering work
Stop work because there are defect in works.
Slab work and Building work and plastering
Slab work and Open window in wall and Plastering
Column roof and Plastering
Cast column roof
Remove form work column roof
Building work
Open window in wall
Electric wall
Slab roof and Building roof in first floor
Building in first floor and Stop work in roof slab
Cast roof slab
Building first floor
A7

12/07/2004 Building first floor
13/07/2004 Building first floor
14/07/2004 Building first floor
15/07/2004 Building first floor
17/03/2004 Slab roof
18/07/2004 Building first floor "B" and slab roof
19/07/2004 Form work lintel first floor "B"
20/07/2004 Slab roof
21/07/2004 Slab roof
22/011/2004 Building first floor "BC"
24/07/2005 Form work roof slab and building work
25/07/2005 Cast lintel first floor and electric roof slab work
26/07/2005 Slab roof
31/07/2005 Lintel first floor and building first floor
01/08/2005 Slab roof and lintel first floor
02/08/2005 Finishing slab roof and form work lintel in first floor
03/08/2005 Building first floor and electric slab roof and lintel first floor
04/08/2005 Slab roof and lintel first floor
05/08/2005 Slab roof and lintel first floor
07/08/2005 Slab roof and building first floor
08/08/2005 Slab roof
09/08/2005 Lintel first floor cast slab roof.
10/08/2005 Building first floor and lintel first floor
11/08/2005 Building first floor and lintel first floor
12/08/2005 Building first floor and lintel first floor
0412/2005 Building work
A8

Appendix (B)
Arena Simulation
Computer simulation is defined by Pristker (1986) as the process of designing a
mathematical-logical model of a real world system and experimenting with the model
on a computer. Simulation has proved to be a valuable analytical tool in many fields.
Particularly, it is powerful when studying resource-driven processes since it provides a
Fast and economical way to experiment with different alternatives and approaches.
Furthermore, key factors in the process can be identified through an in-depth
understanding of the interactions of resources and processes. Construction operations
include many processes. The flow between processes and the resource utilization at
every step thus determines the performance of the whole project. To understand the
interaction of construction processes and the impact of resource supply, the construction
project planner can experiment with different combinations of construction processes
and varying levels of resource supply in a simulation environment to seek the best
performance for their construction operation.
Arena software (Rockwell Software Manual, 2000) is used to simulate and represent the
real system which allows the planners to observe the behavior of the system when
changes are made in the system. Also Arena enables the planners to bring the power of
modeling and simulation to their planning.
Objectives of arena are:
1. It has good ability for the interface.
2. It has good ability to build scenarios.
3. Data entry is easy.
4. Output reports are more comprehensive.
5. It has good animation for the real system.
The following table show the basic elements of arena simulation.
B1

Table B1: The basic elements of arena simulation
No. Name Symbol
1. Create Module
2. Process Module
3. Decide Module
4. Assign Module
5. Batch Module
6.
7.
8.
Separate Module
Record Module
Dispose Module
B2
Description
Starting point for entities in a
Simulation model
The main processing method in the
simulation
Decision-Making processes in the
system
Assigning new values to variables
The grouping mechanism within
the simulation model.
Split a previously batches entity.
Collect statistics in the simulation
model.
Ending point for entities in a
simulation model.

Appendix (C )
Simulation result of the project before applying eight points and after
applying lean tools
C1

Non value added time processes
D4