by Rene Dalmeijer
I have spent many years using and implementing CAD in many fields, ranging from architectural floor plans, electrical ladder diagrams, to CAM [computer-aided manufacturing]. One of my very first major projects was the coupling of Prime Medusa with Oracle to create a BIM [building information model] for the design HVAC [heating, ventilation, air conditioning] systems for hospitals and comparable major building projects. To us back then, this BIM type of capacity was well worth the effort required to implement it, which was and still is a major task.
I like the analogy of leading a canoe through rapids. This is indeed how I often see building projects take place -- not well-planned. As I am a pre-fab builder, I would like to expand the canoe analogy to the way I build. I study the trajectory through the pylons to know which turns are ahead; when I find a missing pylon along the way, I make a suitable adjustment to the unexpected situation. Basically, I have pre-programmed responses by working over the plans using different points of focus. In this way, a good BIM would help me.
The many iterations of hospital designs require extensive configuration management to prevent inconsistencies in the designed systems. For example, a laminar-flow ventilation system for an operating theater may have left the plan some iterations ago:
- A BIM-type system is invaluable to manage this type of complexity, where systems are spread over various types of design documents and 2D and 3D models.
- A PDM [product data management] system might help a little, but is not fine-grained enough to effectively manage all the objects.
- I personally find 2D or 3D graphics are much simpler to grasp than object trees; i.e. the CAD models should be leading and BIM data following.
I hope the above is clear enough to show I still believe in the power of BIM.
My main disappointment, though, is that somehow CAD vendors have not succeeded in delivering effective systems; they are overtly complex to work with, or don't offer solutions to real world problems. As I see it, the best model is an approach comparable to GIS systems where CAD objects have the capability to add/show linked meta data.
I don't believe in pre-cooked systems containing endless structured data models. Each data model is very discipline-specific: an architect's view is completely different to that of the janitor. The structure of a BIM has to fit the specific needs of the parties involved in the project.
I expect that the main obstacle to BIM is that the party who has to fill the majority of the BIM, the architect, is also the one who has the least gain from using it -- meaning architects are not being paid to fill a project BIM properly.
Rene Dalmeijer advises on construction processes, especially in the area of pre-fabricated buildings. He is located in The Netherlands.