Swaps and exchanges
A swap moves a specific serial off a site and another one on, and the counts always reconcile.
Open a swap from the placement’s Units tab, or let a driver’s exception spawn one: a unit he found damaged or missing raises a pre-filled swap for you to complete.
Completing a swap closes the old deployment and opens the new one in one step. Per-class counts are conserved — the yard total cannot silently drift.
A unit can only ever be on one site. That is a database law, not a rule the app tries to follow: a second open deployment for the same serial cannot be written, whatever asks for it.
Do this in SwapProof, free to start
Every stop, stamped.