Crew matrix

The matrix that maps each shipboard position to the rank, certificate of competency, and endorsements the holder must carry, against which a crew manager checks every joiner. It encodes the minimum safe manning document and the flag’s STCW requirements, so a gap, an expired certificate, or a missing endorsement is caught before the crew change rather than at a PSC inspection. The matrix is the operational tool that turns manning rules into crewing decisions.