CC Jan-Feb 2022

TECHNOLOGYfocus
4D Planning
4D planning is the process of applying time plans to
3D models, while the output is a visual simulation of a
construction project, writes David Chadwick
Iwas looking through the wrong end of
the telescope when I spoke to David
Simpson, Global Product Manager at
Elecosoft, about 4D planning recently. I
was focused on the project management
side of the business - the use of
consolidated data to provide the
information that Project Managers need to
make strategic decisions. Whilst this is an
obvious benefit, 4D planning leverages
the mass of finer detail contained within
the BIM model to highlight the day-to-day
activities on site, and to recognise and
deal with issues as they occur.
The most effective way of doing this is to
use an all-encompassing 4D planning tool
that can support the creation of scheduled
timings, activate the components of the
3D model to visually simulate the
scheduled sequence, and capture
progress on-site. This as-built data can
then be used to compare scheduled
progress against the original plan. This is
only achievable if the Project Managers
have detailed information on every
element of construction related activity on
the site, and the commencement and
completion of each task.
This, of course, is made simpler with
Elecosoft's Site Progress Mobile, the
application that keeps on-site managers
and personnel fully briefed on their daily
tasks, providing a two-way
communication to iron out local
difficulties, requirements and requests,
and to sign off tasks when they are
completed.
Properly administered 4D planning has
huge benefits. If tasks in a particular trade
fall behind schedule, it becomes
immediately apparent within the
simulation model what other activities will
be jeopardised and which other trades will
be affected. Steps can either be taken to
alleviate the problem, or to utilise the
software's 'what if' capabilities to explore
some alternative strategies to get the
project back on schedule.
Back to the telescope - I assumed that
considerable effort would be needed to
set up 4D planning scenarios, but much
of the hard graft has already been done.
The data to run 4D planning already
exists. The 4D planning process is reliant
on the architect's 3D construction BIM
model, and the daily task allocation for
each of the trades involved is standard
operating procedure, with the resource
scheduler in each category defining the
human resources, activities and materials
to be used for each task, specifying its
duration and enabling its completion to be
signalled back for inclusion within the
single construction model.
There are still some construction
activities that have to be added to the
architect's model, and these relate to
temporary works, the use of construction
plant, the supply of building components
and material and their temporary
disposition on the building site. I did a tour
of the Hinckley Point construction site
recently, and the most prominent features
were the mass of cranes on-site and the
seemingly haphazard storage of materials
waiting to be picked up and used.
I am assured that with 4D planning each
separate and temporary piece of
equipment, and stored components, can
be modelled and included within a 4D
model, and used as required. Cranes, for
instance, would need their arc of
operation and height limitations to be
included as an attribute, as would the time
needed to erect and dismantle them after
they have completed their role.
VIRTUAL LEGO OR A VITAL TOOL?
Watching a building simulation on screen is
certainly fascinating and very impressive for
potential clients, but beyond seeing how
physical progress during its construction
matches that of the simulated model, what
other benefits does 4D planning provide?
Probably the first that comes to mind is the
most obvious - educating the stakeholder.
As David explained to me, using the 4D
model to communicate with the stakeholder
improves and reduces waste throughout
the entire building lifecycle. What is more,
the further upstream 4D is embedded
within the value chain the greater the
returns. For instance, it gives stakeholders
the opportunity to ask questions and factor
in productivity issues, using the 4D model
as a problem solver and layering in other
factors like cost, facilities management and
environmental concerns and simulating
their effect on the whole project timeline.
Adopting this approach facilitates a lean
methodology, refining and cutting
unnecessary costs in the tendering process
and producing more accurate figures.
Because the whole lifecycle process is
centered around BIM, 4D planning
supports Common Data Environment
(CDE) continuity during the construction
phase of a project and its handover and
subsequent occupation and management.
The biggest benefit, though, is that it
provides a focus for site issues, using the
information provided by on-site trades and
their employees using Elecosoft's Site
Progress Mobile. The commencement,
progress and completion of every activity is
recorded and therefore capable of being
simulated in the 4D model. Should the
project fall behind schedule, it will be picked
up in the model, but more importantly, its
impact on related activities will also be
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January/February 2022