Scope creep is usually described as a people problem: a client asks for too much, a freelancer is too accommodating, or a stakeholder keeps changing their mind.

That framing is emotionally satisfying and operationally weak. The more useful model is a small state machine. Every new request needs to move into exactly one of four states:

Included — already covered by the agreed deliverables.

Swapped — replaces something of comparable effort.

Deferred — recorded for a later phase.