Interdisciplinary check (IDC / squad check)

Engineering disciplines design in parallel and collide in the facility: the pipe routes through the steel, the cable tray wants the same corridor, the equipment nozzle loads the structure someone else sized. The interdisciplinary check is the procedural answer — before a deliverable is issued, it circulates to the disciplines it touches, each reviews for its own interfaces, comments are logged and dispositioned, and the issue goes out carrying the evidence.

The check's value is exactly proportional to the attention paid, which is its weakness. IDC arrives as a deadline-adjacent task in every reviewer's queue, on top of their own production work, and the degraded form is familiar everywhere: signatures collected, interfaces unexamined. The comment log distinguishes the two — a real IDC leaves findings; a ritual one leaves initials.

What the check misses gets found later by more expensive methods: clash detection in the model if the project runs one, and the site if it does not. Every field-discovered interference is an interface that some IDC, somewhere, signed past.