Building Information Modeling (BIM) is changing the way buildings, infrastructure, and utilities are planned, designed, built, and managed. BIM is not a technology, it is a process, and it applies to the design and construction of a building from the design, estimation, supply chain, delivery of goods during the build, the build process, and resource allocation stages right up to the post-handover phase through Facilities and Asset Management. The significance here is to cater to productivity requirements and meet targets.
BIM has gained a lot of traction in the industry; however there is a lack of understanding regarding the usage. Some use it as an advanced CAD tool; others perceive and use it as a series of models that represent different elements of a project. Those who understand BIM and want to derive the maximum benefits however, aim for a single integrated model. They expect to achieve cost savings and hence invest in integrated cost modeling, construction sequencing and facility management.
While, computer aided design – CAD illustrates the geometry of construction elements; BIM illustrates the geometry of an element in 3D, and also associates all details pertaining to this element to the geometry. Thus, an ‘intelligent object’ that carries both physical and parametric information is created. Now every intelligent object/element in BIM knows how it affects and relates to the other object and to the whole building design in general.
Levels of BIM Maturity
A metric of the ability of the construction supply chain to operate and exchange information as applied by the UK Government BIS BIM strategy Report.
BIM levels have been bifurcated from 0 to 3, where level 0 is the simplest form while level 3 defines the highest level of maturity. Here we shall see how BIM is used at different levels of sophistication:
Level 0 is the simplest form of BIM which effectively means zero collaboration – unmanaged CAD, 2D, paper (or ePaper) data exchange. Here 2D CAD and drafting is used for production information. Paper or electronic prints are used as outputs.
BIM level 1 typically refers to managed CAD (2D or 3D), a collaborative data sharing environment and a standardized approach to data structure and format. Commercial data is managed via standalone finance and cost management packages with no integration.
There is a mix of 3D CAD and 2D CAD for concept development and drafting statutory approval documentation and production information respectively. CAD standards are managed to BS 1192:2007, and electronic sharing of data is carried out from a common data environment (CDE), often managed by the contractor. There is a lack of integration for commercial data management via finance and cost management packages. Most of the organizations today are operating at this level of BIM sophistication. While BIM is all about collaboration, at level 1 there is still no collaboration between different disciplines – each discipline publishes and maintains its own data.
Level 2 BIM refers to a managed 3D environment, it adopts a file based collaborative approach and library management. Here commercial data management is done via integrated ERP software tools. Level 2 BIM utilizes 4D construction sequencing and 5D cost information. UK government has called for BIM level 2 implementation across all public sector projects by 2016.
In 2014, the UK Gov. refined its definition of level 2 BIM to include the following seven components:
- PAS 1192-2:2013 Specification for information management for the capital/delivery phase of construction projects using building information modelling
- PAS 1192-3:2014 Specification for information management for the operational phase of assets using building information modelling
- BS 1192-4 Collaborative production of information. Part 4: Fulfilling employers information exchange requirements using COBie – Code of practice
- Building Information Model (BIM) Protocol
- GSL (Government Soft Landings)
- Digital Plan of Work
Level 2 BIM can be distinguished by the higher levels of collaboration – all professionals partake in the process to use their own 3D CAD models however may not work on a single or a shared model. Here collaboration is limited to how the information is exchanged. Shared data is combined and federated into BIM model and interrogative checks can be then carried out.
Level 3 refers to the highest level of sophistication in BIM implementation. This evolved method of working has been set by the UK government as the standard method by 2019 for all public sector undertakings.
This level of BIM will utilize construction sequencing, cost information and project lifecycle management information. Level 3 BIM, will require professionals to integrate design information, costing and information about every element and into a single centrally managed model (a centralized repository shared across all disciplines). This will mean manifestation of a truly and a completely collaborative approach. This model of operation is also known as ‘Open BIM’. However, from where we stand today, there is still a long way to go and using BIM systems of such sophistication will take some time. However there are early adopters, as several larger organizations are making the full use of BIM systems and are very near to achieving level 3 BIM implementation.
Today level 3 BIM adoption, has become the buzzword, and while not everyone is necessarily taking giant leaps towards level 3 – it is certainly looked at with great expectations and hopes like – increased savings in public procurements, improved performance and increased productivity, integrated project delivery, improved operational efficiency that leads to a savings scenario across the lifecycle of a project specifically through reduced demand of energy.
Level 3 BIM implementation also proposes to resolve the current issues such as copyright via robust appointment of documents and software originator/read/write permissions and liability issues by shared-risk procurement routes such as partnering. The CIC BIM Protocol makes provision for these.