Thinking about what I want
Tuesday, November 6, 2007 at 06:54PM
Toby Considine in BIM, Enterprise Interaction

Yesterday, the FIATECH focus group met to review the Capital Projects Technology Roadmap. I sat in as representative for the roadmap’s Element 5. Element 5 is titled The Intelligent Self Maintaining Self Repairing Facility. In case you were wondering, last night’s post was a summary of Element 9 from the roadmap. On the way, I stopped in the Frederick, Maryland, IHOP, fueling up and planning what I would say if they asked me what I, or the 5th Element, required as top priorities.

BIM for Control Systems

No one is using BIM to define control systems. Just as chip design was the last part of electronics fabrication to be computerized, the most technical part of construction is the last to be designed. As the Director of Buildings at UNC once said, “Control systems are designed by a man standing on a bucket.”

BIM for control systems will codify standards for design and develop formal semantics for the services provided by each control system. These system semantics will be linked to the formal performance metrics to measure explicit performance goals. Retro-commissioners know that the problem restoring systems to their original design is that, in many cases, the design does not work. If these systems were fully designed, they would.

Life Cycle Commissioning

Design intents should indicate goals for building performance. When a building model is developed, the energy model should be run directly out of the building model. The energy model should then be compared to the design intents. The energy model, then, becomes a means of commissioning the design against the design intents. The process should be repeated as the design is changed, particularly after value engineering. These energy models then become the basis for traditional commissioning.

The performance goals and metrics developed early in the process are then available to the traditional commissioning agent. The commissioning information should be entered into the building information store to be readily available to service personnel or retro-commissioners.

Since many of the measurements are based upon designed control system metrics, there is no reason not to take those measurements every day – and analyze them as well. Instead of waiting for system components to fail, this would allow regular review of how each system is performing as a system.

Service Oriented Building Systems

One we have the building semantics and building metrics defined during design, then we have the core pieces we need expose control system interfaces as services. No one other than maintenance personnel ever has a reason to issue instructions to a building system except through a service interface. Services hide complex processes and expose only those interactions that are appropriate for the tenant, the landlord, or the enterprise system.

Security definitions of standard roles.

We need standard role definitions to control access to the service oriented building systems. Based upon design intents, the designer can assign particular functions to roles known to the building system. A first pass might be, in order decreasing privilege, Operator, Landlord, Tenant, Visitor, Guest. Maintenance would not be restricted to working through the service interface, and so needs no special role.

Along with roles, we need standards for defining building zones. Zones might be rooms or groups of rooms. They might be determined by cooling system or by security needs.

The job of the building systems integrator then becomes matching control functions and sensor points to zones and assigning internal operations to roles. With identity determined by a third party, the intersection of zones and roles as assigned to each identity provides the basis for secure interoperable building operations.

So that’s my wish list. Too bad I had to leave after one day to go to Grid-Interop…they never got to ask.

Article originally appeared on New Daedalus (http://www.newdaedalus.com/).
See website for complete article licensing information.