PM-STA-0010

An implementation MUST determine an object's State by computation over that object's data. It MUST NOT accept a State as an input, and MUST NOT treat a stored State label as authoritative.

Non-normative: this is the property everything else depends on. A stored status column can disagree with the data it claims to describe, and in practice always eventually does. A computed state cannot. It is also the reason the whole design is auditable: given the data and the model, any past state is recomputable.

It is a one-way door in implementation terms. As soon as a state label is written to a column "for performance", the property is silently gone and nothing will detect its loss. An index over computed state is legitimate; a writable state column is not.