Dependable Production Equipment - Zoomin

zoomin.idt.mdh.se

Dependable Production Equipment - Zoomin

OEE, TPM and RCM

KPP202

Antti Salonen


How a production shift may look!

Productive time

Unproductive time

Planned production time

Start-up problem

Set-up

Break-downs

Planned stopps

Cleaning

Period with small-stops

Period with reduced speed

Production


OEE

Overall Equipment Effectiveness

Purpose:

• Show the disturbances that reduces the productivity of the

equipment

• Show how effective the equipment is used by measuring loss

factors

• Show that improving actions are adequate.

• Aid in planning of resources and workload


The six big losses

• Failures and break-downs

• Set-up and adjustments

• Idling and minor stoppages

• Reduced speed

• Defects and rework

• Start-up losses


What is OEE

X

X

Availability

Performance rate

Quality rate

The OEE-value indicates

the total effectiveness in production


Scheduled working time

Planned

production time

Available

operative time

Net

operative

time

Value

adding

operative

time

Defects

Speed loss

OEE calculations

Unplanned

stopps

Planning related

stopps

Failures and

breakdowns

Set-up and

adjustments

Idling and

minor stoppage

Reduced speed

Defects and

rework

Start-up losses

Planning factor =

Scheduled time – Planning related stop time

Scheduled time

Availability =

Planned prod. time – Unplanned stop time

Planned prod. time

Performance rate =

Bought CT x items produced

Available operative time

Quality rate =

Items produced - Defects

Items produced

Overall Equipment Effectiveness (OEE)

= (Planning factor) x = Availability x Performance rate x Quality rate


OEE calculations

Planning factor =

Scheduled working time – planning related stop time

Scheduled working time

=

480 min - 80 min

480 min

= 0,83

Availability = Planned production time – unplanned stop time = 400 min - 90 min

Planned production time

400 min

= 0,775

Performance rate = Bought cycle time x items produced

Available operative time

=

0,6 min/piece x 412 pieces

310 min

= 0,797

Quality rate =

Items produced – defect items

Items produced

=

500 pieces - 20 pieces

500 st

= 0,96

OEE = 0,775 x 0,797 x 0,96 x 100 (%) = 59,3%

PfOEE = 0,83 x 0,775 x 0,797 x 0,96 x 100 (%) = 49,2%


Three levels of measurement

How to measure

Depending on purpose and aim with the measuring, the following three

levels may be used:

Level 1 Total utilization =

Pftot x A x P x Q

This level indicates how a plant is utilized compared to maximum available

time (24hrs/day, 365 days/year)

Level 2 Asset effectiveness = Pf x A x P x Q

This level indicates how effective an asset is used regarding planned

working hours

Level 3 Equipment effectiveness = A x P x Q

This level indicates how effective a specific equipment is used.


OEE: Total planning factor

Calculation of Pf tot

Theoretical available time (24h/day, 365 days/year) – planning related stop time

Theoretical available time (24h/day, 365 days/year)

Planning related stop time is time loss that doesn’t affect the equipment effectiveness.

For example hollidays, breaks, meeting time, education, cleaning, waiting time due to

surrounding equipment, PM, planned modifications, lack of orders, personell or material.

Note. The use of 24h/day, 365 days/year for definition of Theoretical available time is

common within process industries where heavy investments occur.


OEE: Planning factor

Calculation of Pf

Theoretical production time (scheduled) – planning related stop time

Theoretical production time (scheduled)

Theoretical production time is the scheduled production time when the facility is

manned.

E.g. 3-shift (ca 110 hours/week), daytime (40 hours/week)

Planning related stop time is time loss that doesn’t affect the equipment effectiveness.

For example hollidays, breaks, meeting time, education, cleaning, waiting time due to

surrounding equipment, PM, planned modifications, lack of orders, personell or material.


OEE calculations

Planning factor =

Theoretical production time – planning related stop time

Theoretical production time

Availability =

Planned production time – unplanned stop time

Planned production time

Performance rate =

Bought cycle time x items produced

Available operative time

Quality rate =

Items produced – defect items

Items produced

OEE = A x P x Q x 100 = %

PfOEE = Pf x A x P x Q x 100 = %


OEE: Calculation

Scheduled working time 4x16h + 14h = 78h

Planning related stops 2x5x0,5h + 1h + 5x0,2h = 7h

Planning factor (Pf) (78-7h) / 78 = 0,910 Pf = 91,0%

Planned production time 78h-7h = 71h

Unplanned stop time 1,5h + 3,2h + 1,9h = 6,6h

Availability (A) (71 – 6,6) / 71 = 0,907 A = 90,7%

Available operative time 71h – 6,6h = 64,4h

Bought cycle time 6 min / 60 = 0,1h

Produced items

523 st

Performance rate (P) (0,1x523) / 64,4 = 0,812 P = 81,2%

Scrap

3 st.

Quality rate (Q) (523 – 3) / 523 0,994 Q = 99,4%

PfOEE 0,910x0,907x0,812x0,994 0,666 PfOEE = 66,6%

OEE 0,907x0,812x0,994 0,732 OEE = 73,2%


Defining Cycle time

The following has to be explored:





Manual loading time included

Limiting factors affecting the cycle time

Can several products be produced during one cycle

Do different products have different cycle times


Defining bought cycle time








Cycle time according to equipment specification

Cycle time according to product specification

Lowest CT in similar equipment

Lowest CT tested in the equipment

Theoretically calculated CT

Lowest measured CT

Actual CT recalculated with ambition


Performance rate, P

- when producing products with different CT’s

Product P1 P2 P3 P4

Theoretical CT, CT T (min/piece) 0,6 0,7 0,8 0,9

Produced amount, P (piece)

100 150 50 50

CT T x P (min)

60 105 40 45

Sum CT T x P (min)

Available operative time*, T.O.T (min)

P = (Sum CT T x P) /T.O.T (%)

250

300

83%

* Planned production time – Unplanned stops


Increased OEE leads to….


Less disturbances which in turn may lead to

Improved planning ability


Reduced risk of quality problems

More time for developing work


Released capacity which in turn may lead to

Alternative to capacity investments

Increased flexibility

Decreased operative time

Decreased number of equipments


Time for a break


OEE in Swedish industry (2002)

% OEE Interval Average

60%

50

Improvement potential

88%

40

30

Practically achievable

80%

20

Manufacturing industry

10

Electronics

Mining

Steel

P & P

Power

Chemical

OEE

35-45 45-55 55-65 65-75 75-85 85-95

%


Utilization

Results from a study of 30 Swedish sub suppliers in

automotive industry (Nutek, 2008)

Average OEE = 60,4%

For comparison, a number of similar companies in other

countries were studied:

Average OEE in other countries = 77%

This means that forreign companies have 27,5%

higher productivity in their production equipment!


Utilization

More findings from the study of 30 Swedish sub-suppliers

in automotive industry (Nutek, 2008)

Average OEE = 60,4%

39% of the companies measure and analyze time-loss and cause of failures

14% of the companies measure and analyze time-loss and cause of disturbances

86% of the companies perform systematic preventive maintenance

25% of the companies perform CBM


My own observations

Poor utilization of the possibilities of analyzing data from CMMS

Most companies fail to regard dependability aspects when investing

Few companies use systematic RCA (Root Cause Analysis)

Few companies use systematic maintenance concepts

Few companies measure the cost of lost production


TPM – what’s that

• Total Productive Maintenance

• Total Process Management

• Total Production Management

• And so on….


TPM - definition

• TPM can be defined as a systematic work

• TPM can be defined as a systematic work

method aiming to develop disturbance

free processes at lowest possible cost

through the commitment of all co-workers

(LCP-Consultants)


TPM as a philosophy

– Focuses on daily maintenance in manufacturing

industries, it is built on total employee involvement,

born in the Japanese automobile industry.


TPM – Total Productive Maintenance

• Total Effectiveness

• Total Preventive Maintenance

• Total Commitment


Why TPM

• Replace routine with development

• Increased commitment from all co-workers

• Continuous improvements

• Foreseeable operations

• Improved safety and environment


Safety, hygiene and environment

TPM Structure

Evaluation and new goals

Preparation Implementation

Early equipment management

Quality maintenance

Effectiveness

Effective administration

Continuous improvements

Autonomous maintenance

Planned maintenance

Education and training

Kick-off

Management’s decision

Education

Organisation and pilot

Policy and goals

Develop a master plan


Group activities

Cross functional improvement group

Autonomous maintenance group

Target oriented cross functional group


Quality improvement tools

7QC/QM

Identify, prioritize and analyze failures

FMEA

Identify and evaluate potential weaknesses

FTA

Identify causes of failures and their logic connections

PM-analysis

Reduce all chronic loss to zero


Autonomous maintenance


Autonomous maintenance

• Teach the operators to react on cause instead of result

• By increased kompetence and understanding the operators may:

– Eliminate minor stoppages

– Prevent break-downs

– Secure implemented improvements

– Improve quality, safety, and environment

• In the long run operators start to perform maintenance tasks

• Daliy inspections replaces repair and low frequent controls

• Implemented through seven well-defined steps

• Takes long time to implement, often years


The seven-step ladder

Equipment

focusing step.

Secures the basic

condition of the

equipment

Focuses the operators.

They learn advanced

inspection and

maintenance techniques

Description

Factory focusing step.

From maintenance to

control.

3. Standards for cleaning and lubrication

2. Counter meassures at the problem source

1. Basic cleaning and order

6. Organize the work environment

5. Autonomous inspection

4. General inspection training

7. Autonomous maintenance

Can find defects and

understand the principles for

improvements of the

equipment

Understands the

functions and structure

of the machines

Competence

Repair skills

Understands the

relation between

maintenance and

product quality


Planned maintenance

Activities for improved OEE

Information feedback

Maintenance planning

Maintenance control

Spare part control

Economy control

Activities for improved

maintenance effectiveness

Corrective Maintenance

Preventive Maintenance

Restoring Maintenance

Improvement Maintenance

Condition Based Maintenance

Implementation of planned maintenance leads to:

-Increased MTBF and MTBM

-Decreased MTTR, MWT and M

-Closer to 0-faults, 0-stops and 0-accidents


Early equipment management

The process has to goals:

•To reach stable, full speed production at start-up.

•To, as far as possible, meet the detailed

requirements for the equipment.

Goal and

requirements

Project

Basic properties

Acquisition process

LCC

Structure and process thinking

Experience development

MP-design

Early detection of

problems

The included activities are aiming for new equipment to be:

•Reliable and producing non defective products.

•Easy to mend and set up, and fast to start after set-up changes.

•Easy to maintain, and fast to localize faults and repair.

•Easy to clean, lubricate and inspect.

•Resource efficient and safe.


Quality maintenance


Results of TPM at Volvo

Productivity Breakdowns reduced with 90%

OEE increased from 50% to 90%

MTBF increased from 30 minutes to 8 hours

Quality Scrap reduced with 90%

Cost of quality control reduced with 67%

Customer complaints reduced with 75%

Costs Production cost reduced with 30%

Delivery precision Capital bound in WIP and finished goods decreased with 50%

Fulfillment actual/desired delivery time increased to 90%

Delivery precision actual/promised time increased to 100%

Safety Accidents resulting in personal injuries reduced to 0

Accidents resulting in pollution reduced to 0

Commitment

Ten times as many suggested improvements

Time for education and training increased with 100%


RCM – what’s that

RCM has been defined as…

Reliability Centered Maintenance: a process used

to determine what must be done to ensure that

any physical asset continues to do what its users

want it to do in its present operating context.


RCM

• Reliability Centered Maintenance, RCM

– Focuses on construction and development of

products and manufacturing systems

maintainability and to develop an effective and

resource parsimoniuos PM before the product or

system is up and running, born in the aircraft

industry


Reliability Centred

Maintenance, RCM

• RCM is sprung from MSG (Maintenance Steering

Group) that has been developed since the 1960s’, for

the purpose of the aircraft industry.

• RCM have since also been developed to be used in

e.g. the power industry, energy industry, and in some

cases also the manufacturing industry.


Reliability Centred

Maintenance, RCM

• With RCM methodology one handle the maintenance

objectives as early as in the development phase on a

consciously, rationally, and planned base.

• One analyses potential failure that can occur on the

developed systems, structures, or components.

• Faults can be classified as obvious or hidden, safety

critical or of considerable financial character.


RCM

RCM is basically about answering…

• …what are the functions and associated performance

standards of the asset in its present operating context

• …in what ways does it fail to fulfill its functions

• …what causes each functional failure

• …what happens when each failure occurs

• …in what way does each failure matter

• …what can be done to predict or prevent each failure

• …what should be done if a suitable proactive task

cannot be found

• This can be performed through e.g. FMEA and FTA


Further reading

Total Productive Maintenance (TPM) Concepts and

Literature Review, (Pomorski, 2004)

Reliability centered maintenance, (Rausand, 1998)

A review of overall models for maintenance

management, (Sherwin, 2000)

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