A BIM PERSPECTIVE

I recently read an excellent article by Martyn Day in AEC Magazine: “BIM is not CAD”. It discusses the lack of foresight in assigning a CAD Manager to implement BIM. It presents a perspective of BIM as something to replace CAD, something that is “more than CAD”. But is that the case?

What the advent of BIM has allowed certain people to do is perpetuate the “bandwagon” approach that CAD Managers are not capable of delivering BIM, that it’s the responsibility of all the company, from top down. It is, no doubt, but only because it now permits a muted view of what CAD Management should always have been, and assumes that CAD systems were flawed. For me the article highlighted a more fundamental issue I’ve always had with CAD Management: I would argue that exactly the points Martyn raises as being essential to BIM implementation are, and always have been essential to effective CAD Management.

Part of this is semantics, but to now dismiss “CAD” as 2D draughting is somewhat hypocritical when it is a commonly held opinion that “you cannot get to BIM just by buying BIM software”. Equally, you could not achieve CAD by buying CAD software – whatever “CAD software” (or “BIM software”) actually is. Understanding the difference in those semantics is critical:

  • Software is a “program used by a computer”, or for this point of view, the product you can buy from a reseller or vendor direct. It requires a license to run it legally, and would include packages such as AECOsim Building Designer, ArchiCAD, AutoCAD, AutoCAD LT, BIMsight, Excel, MicroStation, Model Checker, Navigator, ProjectWise, Sketchup and Revit, among many others. Some of these could be classed as BIM software, some as CAD software, but those classifications are totally subjective, even arbitrary. It is what the software is used for that defines it.
  • A System exists when software is implemented as an “interconnected network; a complex whole”, working to “a set of principles” in an “organised scheme or method”. CAD software becomes a CAD system when it is managed, when it has standards applied, and delivers as part of the building process. BIM software becomes part of a BIM system when… wait for it… it is managed, has standards applied, and delivers as part of the building process. Only for some reason the BIM system is perceived as superior because someone writes a white paper about it for your senior managers and has a government strategy group.
  • The Process is a “series of actions or steps taken to achieve a particular end”, in this instance to deliver a project. Process was, and always will be, the underlying requirement for any system implementation. The Systems support the Process, using Software as the delivery mechanism.

Implementation of a Building Information Modelling system is not a black or white affair: you do not change your delivery mechanism or processes overnight. Adoption, if it is to be successful, must be staged. A series of targets should be identified, and a strategy put in place to achieve them over a set period of time. It is a commonly held misapprehension that BIM implementation is a failure if it becomes necessary to revert to traditional production methods in order to deliver a project. On the contrary, this is both a sensible and pragmatic possibility that should be embraced as part of the adoption process. It is difficult to legislate for all eventualities, and at times it may be necessary to drop idealism in favour of profitable production. Which is better: to continue obstinately with a new and unproven method and cause a project to fail, or to use whatever means necessary to ensure the clients design is delivered on time and on budget? The process should be monitored, measured and analysed to identify what could be improved next time around. Every project, whether BIM is adopted fully, partially, or abortively, should be a learning process, allowing a strategy to be eventually accomplished.

Inexperience is not a fault, an assumption that “if you cannot make it work fully first time you have failed” is. In an ideal world, the BIM strategy will have identified a series of steps, with a focus on “quick wins” to demonstrate successes over an extended period of time. That is something which “experts” have the benefit of hindsight for – they started on their journey once too, and didn’t all get it right first time – yet others who are tasked with delivery of new methods and technology are judged against their expertise. Errors, mistakes and unforeseen circumstances occur (often because of misguided planning or an inexperienced strategy), but these are not failures unless allowed to become one. All it suggests is the strategy needs revision, that the benefits have not yet been realised. It is the role of a good manager to ensure the reasons for any abortive work is identified, reported and addressed.

You do not have to convert your office to a fully immersive BIM environment immediately. It is perfectly acceptable to install and use BIM software for modelling and perhaps drawing production alone as a first foray into the wider procedural challenges. Regardless of what the “experts” define “true BIM” as, you should remember that BIM is defined in UK standards using a sliding scale visualised in the BIM Maturity Diagram. Finding a position on that graph that both prepares your company for future change and reinforces the ability to provide continued robust project delivery is merely the first step.

The issue of effective delivery relates to the title “CAD Manager”, a now demoted (and demotivated?) position, regarded as not relevant in the idealistic BIM world. What is a CAD Manager, and how do they differ from a BIM Manager? In my opinion, the only difference is the acronym tagged on the start. A bad CAD Manager is a bad manager, as much as a bad BIM Manager, and vice versa. To say that a BIM Manager has to have a “wider level of responsibilities”, that they need to “understand project workflows, how buildings are assembled, teams, fees, structure”, etc, misrepresents my understanding of CAD management; it is as true for someone managing a CAD system as it is a company undertaking BIM. The somewhat blinkered perspective that CAD was fundamentally flawed and CAD Managers were not capable of understanding building design says more about the self-promotion of BIM than it does about the responsibilities of a good or bad CAD Manager. In future, wherever you see or read the virtues of a BIM Manager, or the roles that a BIM Manager should undertake, simply replace the “BIM” acronym with “CAD” and you’ll have an idea of the role of a decent CAD Manager too.

CAD means “Computer Aided Design” and is used to “assist in the creation, modification, analysis, or optimisation of a design”. Surely BIM falls into this definition 100%? BIM is exactly CAD, it’s just the perspective of what CAD should be has become myopic with the advent of modern BIM spin. Finally the industry is being given the catalyst to return to true Computer Aided Design values that should always have been prevalent.

Photo by Stephen Crowley on Unsplash