Figure 1 – a perspective on stages of maturity of analogue and digital information management (Permission to reproduce extracts from British Standards is granted by BSI Standards Limited (BSI). No other use of this material is permitted.)
Importantly, the stage of BIM maturity is not related to ‘dimensions’ in line with the n
D modelling philosophy4
. The n
D modelling philosophy assigns dimensions based on purpose, typically accepted as:
- 3D = 3 spatial dimensions
- 4D = Time. Attributes are added to allow construction sequencing, etc
- 5D = Cost. Attributes are added to allow cost
- 6D = Facilities management (FM). Attributes are added to allow asset/facilities management
There is no real agreement beyond 5D. For example, 6D is sometimes ‘sustainability’ and sometimes ‘FM’. Some companies state that they are working at Level 7 because some of their models are used for FM or sustainability purposes.
The Institution’s BIM Panel do not recommend using nD modelling terms beyond 4D. Even cost (5D) is not really a ‘dimension’.
The stage of BIM maturity is essentially a measure of how well each party’s information is structured for use in federation by a collaborator without requiring significant remodelling for their process.
The stages of BIM maturity can be summarised as:
- Stage 0: Undefined
- Stage 1: Partially structured unfederated data. This can be achieved through National Standards of naming and layering standards, common origin points, orientations
- Stage 2: Structured federated information models. The parties are working in their own isolated BIM models and then sharing and coordinating information using a Common Data Environment (CDE) for federation. Based around the principles outlines in the BS EN ISO 196502 series of standards
- Stage 3: Server based object information models hosted on queryable database Common Data Environments. Companies claiming to be working at stage 3 are doing so before the formal definition has been agreed
Note the following:
- Just because a 3D model is being produced in a recognised BIM authoring package, does not mean a party is working to stage 2 BIM. If the information within that 3D model is unstructured and difficult for collaborators to federate and use within their processes this is most likely stage 1 or below
Stage 3 is yet to be fully defined. There are currently pathfinder projects investigating stage 3, but no project in the UK has been delivered at stage 3.
What constitutes working at BIM stage 2?
Documentation can still be a contractual deliverable:
To work effectively at stage 2, the following requirements should be met:
this could include 2D drawings, schedules, etc. that originate from BIM authoring tools and supplementary information such as reports and speciﬁcations. To align with the requirements of stage 2, the deliverable should be in a consistent digital format that is ready to be federated with other models. The delivery format is recorded in the BIM Execution Plan.
A 3D model is being issued as a deliverable:
this could include 3D models created in BIM-enabled software, eg a native ﬁle such as Revit, Tekla, ArchiCAD, etc. or a non-proprietary Industry Foundation Class (IFC) ﬁle containing the same information. The format and digital structure of this information is recorded in the BIM Execution Plan.
Non-graphical data is issued as a separate deliverable:
this could include information that may be important for collaboration, co-ordination, future asset management or other activities. These non-graphical formats are defined in the BIM Execution Plan. One notable non-graphic format, COBie, is outlined in BS 1192-45
These requirements should be transparent and consistent between team members. This greatly increases the ability for team members to exchange information and avoid duplication and remodelling. For this to work effectively the projects should use:
- Data standards
- Deﬁned processes. The two most important documents are:
- Exchange Information Requirements (EIR): this document defines the general information requirements and establishes the specific information management requirements, and is part of the tender document for the procurement of the design team and constructor
- BIM Execution Plan (BEP): this document details how the team will manage the digital information throughout the project in compliance with the EIR
- Controlled data exchange: eg what information, what format and how often?
- Common Data Environment (CDE): the CDE is deﬁned as a single source of information used to collect, manage and disseminate all project documents. At the basic level this could be achieved using an advanced project extranet site
Most structural engineers will recognise that they are capable of operating somewhere between stage 1 and stage 2 (see figure 2).