Tokens indicate intent, not full custody
A token hanging where a tool used to sit can indicate who removed it. It cannot reliably show the aircraft, work order, bay, expected return, calibration state, or transfer history.
Digital custody does not need to discard physical tokens during a pilot. It should make the operational record reliable while the physical process remains familiar.
The current holder must be singular
A tool cannot have two active custody records. If a system allows that, every downstream report becomes suspect.
Issue, handoff, return, missing-tool investigation, and calibration dispatch should be transactional state changes with idempotent behavior and audit evidence.
Mechanics need speed, not paperwork
The mechanic-facing workflow should be fast enough to beat informal behavior: scan, confirm valid tool, issue, and move.
The store and quality teams get the richer record automatically, without asking mechanics to become data clerks.