In
the AEC industry, the advent of building information
modeling (BIM) concept was viewed by many
as an evolution to better 2D and 3D computer-aided design (CAD) techniques.
Very few saw it as an interdisciplinary, collaborative tool that would
drastically change the design-build project workflow, the management structure
of AEC firms, the teaming models, the delivery standards, and the role of key
disciplines involved.
As
opposed to the vertical communication channels and delivery methods required by
the traditional design-build approaches which mainly employ CAD, BIM
necessitates an open and integrated horizontal collaboration channel between
all the key stakeholders of the project: facility owners, designers/architects,
MEP (M&E) engineers, consultants and contractors. To realise the benefits
of employing BIM
services as compared to 3D
CAD modelling tools, firms need to significantly invest in knowledge/skills
development, personnel training, management restructuring, and software tools.
However, more than these tangible investments, AEC companies need a complete
change in mindset in case they want to adopt BIM for their projects.
Whilst
many professionals, especially those from small and medium-sized firms, see it
as an extension of 3D CAD, BIM is anything but 3D CAD. BIM
services involve extensive
pre-construction planning and multidisciplinary coordination to virtually model
building facilities using smart parametric objects embedded with rich accurate
information. This intelligent model then can be used by all stakeholders to
extract respective views and relevant information thereby resulting in timely
decision-making and project delivery.
Though
BIM and 3D CAD are not mutually
exclusive to each other, they have major differences as far as the approach and
the output is concerned. In traditional 3D CAD, depending on the scope of
project, architects prepare a set of construction drawings, including the
plans, sections, and elevations. Since all these views are independent
entities, any change in one view has to be manually updated in others. As a
result, the process is not only time-consuming but also increases the scope for
errors.
On
the contrary, a building information
model contains the architectural, structural and MEP system models of the
proposed facility. It is prepared during the design and planning stage using
details from all the key stakeholders including designers, engineers, MEP
contractors, and subcontractors. Since a single database-driven model
represents details required by all disciplines, any changes made by any of the
team members are automatically updated across the model to plans, sections and
elevations. Hence, all the project team members are updated on all the changes
made by others thereby saving time, reducing cost resulting from duplication of
efforts, and increasing the overall quality of construction drawing sets. As a result, making small changes to the
architectural plan would result in those changes appearing simultaneously in
the section, elevation or schedule for the same change to the plan.
Furthermore,
the building blocks of 3D CAD models
are lines, circles, arcs, and other graphical entities, which lack the
flexibility of data analysis. These models only serve as geometric objects
devoid of detailed parameters which are required by the entire AEC supply chain. In contrast, BIM
models comprise building elements and intelligent systems, including columns,
beams, and walls, which contain rich data related to parameters. If needed,
additional parameters can be added to the pre-existing ones for more detail.
And, this rich data can be effectively shared across disciplines for rich collaboration
and on-time delivery.
Nevertheless,
the success of any project which employs BIM depends mainly on factors which
include the richness of information embedded in the 3D models, the degree of
openness in the interdisciplinary data-sharing and collaboration standards, and
the level of mutual trust among all the professionals involved. If prudently
planned and implemented, a BIM model
not only represents the essential building elements in detail; valuable
information concerning spatial coordination, geographic location, quantity
take-offs, material requirements, time schedule, and project cost can be
extracted when needed.
In
essence, well-planned BIM services
help accurately represent the entire project design lifecycle. Though preparing
for and implementing BIM strategies requires considerable investment of time,
money, and effort, its benefits are multi-faceted and long-term. Employing BIM
modelling can not only help in more effective design and construction but also
offers pre-fabrication and facilities management advantages.
