Architecture, engineering and
construction (AEC) industry has seen the fall of its productivity and work
efficiency over last 50-60 years. Key statistics on the official website of UKGBC quotes “About 400 million tons of
construction material is delivered to the construction site each year, out of
which almost 60 million goes straight to waste due to inappropriate ordering or
damage.” To general contractors and construction engineers, this is not only a
concern of materials wastage but also their planning and time management. It
consumes additional time to plan the schedule and timings with new ordering.
So how can general contractors
and construction engineers get out of this vicious circle of planning and
re-planning? Obviously, trying and implementing a method that has already been
proven to be a success elsewhere, such as practicing principles of lean manufacturing
for building construction projects.
Attaining Coordination & Eliminating Redundancy
With implementation of BIM Level
2, lean practices come invariably. BIM implementation for construction project will
eliminate most of the redundant tasks causing waste of time and planning. However,
the current situation of annual waste statistics for the UK, as mentioned
above, indicates that this isn’t the case.
For any building element, the
ways of looking, perceiving and designing is different for various discipline
and hence the design will have as many versions as the disciplines. Say for
example, for an architect the building wall is about the outer look and
finishing; for a structural engineer it deals with the steel and concrete
material for strength; and, for a facility manager it is to see the maintenance
to have it sustained the way it was built originally. Thus, one building
element has several ways of perception and as many drawings in several
different software.
With design coordination on a common
platform, as offered in BIM Level 2; differences in designs are viewed from a
holistic approach. BIM solutions would integrate various steps of design
detailing and coordinating construction processes.
BIM solutions for building construction projects focus on creating a 3D model, incorporating details from all
disciplines; architectural, structural and MEP. It helps with a collaborative
approach for quantity takeoffs to avoid any mistakes in planning. Designs for
fabrication, from such BIM-ready 3D models essentially, integrate cost and
scheduling data. It eliminates repetitive tasks of evaluation and empowers site
managers to manage construction activities efficiently.
Well organized schedule is must for Lean Approach
Most of the waste results from
rework that takes place, due to improper alignment of activities, on any
building construction site. The solution to eliminate waste lies in
implementing BIM enabled construction sequencing with lean construction
principles. It allows creating and maintaining work orders across construction phases
and also during later stages of facility management.
Simulating construction process
in a digital environment empowers general contractors to maintain and control
supply chain by accurately planning the logistics. The knowledge of exact
location and expected time of delivery of pre-fabricated building elements
gives these contractors a sense of better judgement of delivering the ordered
quantity at correct construction site location. Efficient and safe operations
can be guaranteed by eliminating unnecessary delays due to idle time or reworks
during the entire project.
To justify this, reductionof 30-35% in budget was observed resulting from reduced waste and reworks by
using BIM with LOD 300 during the construction of a hospital in Egypt. Instead
of going the traditional way, the construction firm decided to move ahead with
BIM and the engineers at design support firm developed architectural,
structural and MEP plans and developed a BIM ready model for the hospital. Information
pertaining to construction from such intelligent BIM 3D model resulted in
achieving proper coordination of activities.
Adopting Efficient Construction & Installation Process
When building elements are assembled,
key aspect to be considered by site engineers is about logistics and
installation process. The comprehensive understanding is necessary in order to
optimize the methods with minimum rework and follow lean construction approach.
Transportation, shipping weight and their charges; formworks, etc. are some of
the many key factors deciding construction processes. Say for instance, offsite
prefabrication of building elements has proved to be efficient in terms of
productivity and costs.
Ideally, MEP connections as part
of BIM process, in the designed layout are the most difficult to manage and
install on site. But prefabrication of partially completed MEP panels can aid
well and manage installation easily. It is because of weight difference in partially
and fully fabricated panels; and the panels serve as formwork on their own. Near
site fabrication and a final on site installation can eliminate the issues
related to space, transportation, and risk to damage during transportation,
etc.; thereby reducing the waste.
Conclusion
Today, most of the leading
construction firms have adopted BIM as several governments have mandated BIM, and
Netherlands is following the footsteps. What
needs to be done is implementing the idea to focus more on the construction
process leading to fine & efficient facilities. Adapting the principles of
lean manufacturing to construction alongside BIM can create wonders in reducing
the waste currently produced in the industry.