Clash detection

Clash detection federates the discipline models — piping, structural, electrical, HVAC — and searches the union for interference: hard clashes where objects intersect, and soft or clearance clashes where required space (access, maintenance envelopes, insulation) is violated. It runs in cycles as the models develop, feeding coordination meetings where clashes are assigned, resolved and re-checked; every clash resolved on screen is a field rework avoided at a fraction of the price.

The practice's realities are managerial. A first run on a large model returns clashes by the thousand, most of them duplicates, trivialities or artefacts of modelling style, and the craft is in the rules and triage that surface the hundred that matter. And a clash-free model is a necessary condition, not a sufficient one: the software checks the finished geometry, not whether the pipe can be installed — erection sequence, welding access, pull spaces — and it checks only what was modelled, at the LOD it was modelled to. The clash report inherits every limitation of the model beneath it, silently.