How many of you have seen this “BIM maturity” diagram before?

I’m guessing either never or so many times that it makes you groan. This was “originally” published in the “BIM Working Party Strategy” in 2011 as part of the explanation as to how construction information develops from dumb CAD through the addition of systems, methods and standards into intelligent and ultimately a fully interoperable single environment. (I say “originally” as this diagram was doing the rounds in Mark Bew and Mervyn Richard’s presentations well before that document saw the light of a download button.)

Here’s how BIM maturity works:

You start your journey up the ramp at Level 0. Level 0 is good old trustworthy but not especially intelligent CAD data, where you are working on a “digital drawing board”. Data sharing is very “insular” as each person is working to deliver their own documents without consideration for structure, re-use or co-ordination.

Moving up towards Level 1 sees the CAD data beginning to take on standards and consistent structure. Information is spatially coordinated and information is broken down into logical groups, either by layer standards, references, folders or a combination of methods. This allows data to be shared far more effectively, and the segregation of data in an ordered manner assists with removing the need for re-working. The cross-over point between Level 0 and Level 1 would be where the design team all share coordinate systems and all work is drawn in a coincident manner, and where model data is exchanged as opposed to “flattened” drawings.

Progressing up though Level 1, more 3D working is introduced to help assist with geometric design and coordination, although this data may not yet have any intelligence associated with it. (Note: visualisations and SketchUp models should not be considered part of Level 2 as these are typically built in an insular manner and have no consistent data structure that can be re-used.) As Level 2 is approached, projects will have a common method of producing, exchanging, publishing and archiving data. CAD files are no longer considered drawing-focussed but are built to define wider project requirements and are used to produce other project documentation.

The switch to Level 2 occurs with the adoption of Building Information Modelling. This does not mean using Revit or AECOsim, but by collaborative and process-led authoring, exchange and publication of data. More and more consistently through the Level 2 ramp added intelligence , metadata, will be included in the “model”. (By “model” this does not necessarily mean a 3D model, but the assembly of individual files, 2D and 3D and non-CAD data into a unified “container”.) The metadata will be used for schedules, specifications, and in a raw format in the required-but-no-one-is-really-sure-why COBie spreadsheets.

At the top end of Level 2, projects will have Project Execution Plans defining how BIM data is to be structured, the level of detail produced at each stage, and a basic requirement for data exchange. The supply-chain also begins to be involved, and in some cases the Client will also specify what expectation and requirements they have of the data. Construction is still carried out from the drawings, but coordination, project schedules, procurement and ultimately asset management use other interrogative methods of the data to increase efficiency. PAS1192-2 (Currently in the public consultation stage) specifies a list of criteria to meet for Level 2 BIM, including:

  • Clear employer’s information requirements (EIR –you gotta love those TLAs)
  • Contractual inclusion of all sub-contractors and supply chain into the BIM process
  • A shared data environment
  • Adoption of BS1192 and PAS1192-2 processes
  • And other non-specified arbitrary requirements

The last point is particularly weird for a document intended to become a British Standard in the future. Adding a clause “This list is not exhaustive” more or less states “other things we can’t be bothered to specify”. Imagine the BS for safety glass, or unleaded petrol stating: “you’ve got to comply with a bunch of important stuff, but there some other things you need as well… but we don’t really know what they are.”

The bad news is, if you have to adhere to all those principles, that no-one is yet doing BIM Level 2, and in many cases, outside of large, well-resourced organisations with BIM-savvy clients (and there are a whole host of those around aren’t there?) you’re not able to cross that Level 1 CAD / Level 2 BIM threshold. But people are working in a BIM environment. Yes, it may be closed, selfish BIM, or it may be slightly more open, where the main parties are exchanging protocols and PxPs, but it is BIM. That cannot be denied. So what is it they are doing? According to this diagram, it’s not Level 1 CAD or Level 2 BIM. Maybe it’s a Level 1.5 BIM…? Or maybe it just reflects on the purpose of PAS1192-2 in the first place: a document intended to guide delivery of data on public projects which is being picked up by the private sector as well. It’s an aim, an aspiration, for 2016, although I suspect it will take longer to iron out the inconsistencies and actual detailed technical requirements which are noticeable by their absence at this point in time. Level 3 is also an aim. It’s the utopian ideal of BIM, spoken about since before BIM was called BIM. An admirable target? For sure. Achievable? Not for a long while.

It is interesting that the documents listed are all strategic, not technical, in their content. For an almost exclusively technology-enabled process it is still surprising that the UK is avoiding the question of technical authoring & design standards, at least for now. The missing piece of the puzzle, the technological enabler is a UK-specific BIM standard that tells you exactly how to configure your BIM software to deliver these goals which is available as the AEC (UK) CAD & BIM Protocols. Not a standard in and of themselves, the AEC (UK) documents provide an implementation of the frameworks outlined in BS & PAS1192 specifically for Autodesk and Bentley products. The scope of these covers Level 1 CAD as well as Level “1.5” and Level 2 BIM and can provide a common structure for projects using multiple platforms.

But what about Level 3? BIM Level 3 is the utopian definition of BIM which was first used to tout its benefits way back in the days of Jerry Laiserin, It means a fully interoperable, immersive BIM environment where all individual BIMs are part of a complete project model, regardless of software, regardless of location. For those of you who think that is just a convenient method to segregate the “big boys” from the other 99% of the industry, you may well be right. I don’t think it was intended that way, but as with all things BIM, the bandwagon has already begun to roll with claims of “Level 3 BIM” from contractors, consultants and software vendors alike. Here’s a piece of advice should you be fooled by any of these peoples’ clever lines: you can’t “do” Level 3 BIM. It doesn’t exist. At the moment BIM is exclusively stuck on Level 2 with “closed” systems that only work if you own the complete suite of products from a specific manufacturer. If true Level 3 is to be reached, then it should not matter whether you are using Autodesk products, Bentley, Graphisoft or Excel, Word or Sketchup as any software package to claim it is BIM Level 3 enabled would be that it can read and/or write either the graphical elements or the metadata directly without translation and without loss.

Confusingly, IFC is included as Level 3 BIM. IFC has a tendency to be touted as the complete solution to all of our data interoperability needs, but alone it is not an indicator of Level 3 BIM. IFC in fact, at the moment, is nothing more than a limited and often ambiguously interpreted standard which causes more problems than it solves. There are other, much more robust, ways of exchanging integrated graphics and data, but all of those methods require a specific approach depending on what collaboration software you happen to be using. IFC can help, but at the moment it is firmly entrenched in a Level 2 translation-based export and import process.

Perhaps the diagram needs revising to give a more realistic image of BIM maturity; perhaps it is more realistically a diagram that describes the stages necessary for PAS1192-2 compliance rather than all stages in BIM maturity. The purpose of the diagram is to give context to the framework requirements of PAS1192, the “Publicly Available Specification” for capital delivery of construction projects. BIM Level 2 is a target rather than a definition, although if its targets are achievable, I suspect it will become a definition not long after the 2016 “deadline”. The aspirations of PAS1192-2 are to provide a standardised structure of roles and documents to ensure the delivery of project information in an effective and reusable manner. There are gaps, there are grey areas, and there are way too many acronyms, but it is something the UK construction industry needs. It gives a consistent approach to Building Information Management – at least in the context of the construction phases of a project. But there is a long way to go before many projects are in a position to claim “Level 2 BIM”. A lot of time and effort is needed to realise the criteria outlined above, which do not appear to be fully defined or understood by those specifying them, hence the PAS moniker; everyone is still learning what this means and how it will work. We will, I guarantee, see changes in the requirements of delivery, or at least a much more detailed refinement in the “supplementary documents” that are promised.

BIM Level 3 gives the industry something to aim for beyond that. It’s nice to have a long-term goal and, if nothing else, gives the software industry something to spend their marketing budgets on. It is, however, a target that should be ignored for now if you are serious about delivering BIM. I was going to conclude this briefing on BIM maturity using the article title’s travel analogy: you cannot reach Level 3 without having passed through Level 2. But then, having thought about where we are with project process, with technology and the insular, self-centred nature of software developers, and I realised the closing sentence should be a lot simpler: you cannot reach Level 3. Besides, doesn’t the four year target for Level 2 compliance give you enough to worry about?

Photo by andrew welch on Unsplash