Saturday, August 7, 2010

Notes from the Field (BIM)

As we start getting deep into our first project that is taking advantage of using a BIM for Subcontractor level Spatial Coordination  (also called Clash detection and Trade Coordination) I thought I would post a series on what we are learning. 

If lack of knowledge and inexperience combine to form mistakes, then repetition (to gain experience) plus the ability to learn from your mistakes (knowledge) combine to form wisdom (the ability to avoid mistakes similar to those you’ve made in the past.)  The problem is, that it takes some of use longer to gain experience than others.  And, some of us (even when we gain knowledge) can’t make the jump to wisdom to avoid those darn mistakes. Whew, thank goodness for repetition.  :)

Round 1:

  1. You are only as strong as your weakest link.
    • While I think we all know this at heart, make sure that the weakest link is strong enough to perform at an acceptable level or everyone involved will be disappointed.
  2. BIM does not guarantee a reduction of duration for any particular project phase nor the whole project (even though that is one of the goals of using BIM.)
    • If you don’t have the ability to sequence your work and estimate effort and duration for your scope of modeling, you can “chase your tail” for a VERY long time. (BTW, most field staff already have this essential skill. Make sure they understand that your BIM effort relies on their skill as much as your construction/installation effort does.  It’s literally virtual BUILDING!)
  3. No one truly cares about BIM Coordination… until they find an issue that costs real dollars or causes quality to suffer.  You can’t cajole, intimidate, or fool people into respecting what 3D spatial coordination can do until they are involved in it themselves.
  4. Just because an object is “out of the scope of modeling",” doesn’t mean it won’t cause issues during construction. (Put simply: What you don’t model will be what causes issues during construction.)
    • Evaluate what you do and don’t model very carefully.
    • While some object’s size and installation method or sequence make them easy to reconfigure in the field, it still takes time and thought to plan and perform that reconfiguration.

Finally, for your viewing pleasure, a collection of “clashes” from a recent project.

Interference Slide Show


David Kingham said...

I like how you put the room names above ceiling, that never occurred to me (duh!) I had only been putting them at floor level. I assume you exported to cad for the room names?

Erik said...

We did export a CAD file for room names and gridlines, since they are annotation objects and don't show in 3D in Revit.

We also have a 3D grid that I pulled off of AUGI and modified a little.

I tend to move the room names up and down a alot with the File Unit/Transform command. I place them above the ceiling when looking at Systems coordination in that area and drop them back to just above the floor when sectioning the model and looking at "Floor Plans."

tgov said...

This is a timely post, relative to recent discussion with a client! As I like to say, clash detection isn't going to automatically 'fix' your model, but it sure helps identify things you didn't notice were broken. Thanks for providing more elegant phrasing!