Backtracking for a missed check can cross clean and dirty flows.
Map the flow
- Main direction
- Return reason
- Exception bay
- Re-entry condition
Separate exceptions. Set side areas for missing accessories, failed checks and quarantine without blocking the main path.
Verify in the field. Observe returning units; record the reason and re-entry decision.
Floor arrows are not enough; materials and authority must be at the right point.
