Scope creep

Scope creep is the steady growth of a project past what was agreed, one reasonable-sounding addition at a time. No single request is unreasonable. That is the mechanism: a change that would obviously be refused as a lump is accepted as a sequence.

What makes it expensive is not the work added but the work displaced. A project that grows twenty per cent does not finish twenty per cent later; it finishes late enough that the next three things slip too, and the person who agreed to each addition never sees the bill because it arrives somewhere else on the calendar. This is why teams often experience scope creep as vague overwhelm rather than as a specific decision they can point to.

The practical defence is not saying no more often. It is making the trade visible at the moment of the request: this is possible, and it moves the delivery date by nine days, or it replaces one of these two items. Almost everyone accepts a trade they can see. Almost nobody volunteers to withdraw a request when the cost is invisible.

A concrete case: a website build agreed at six pages picks up a blog, a newsletter integration and two extra languages over five weeks — each approved in a single message, none re-quoted. The finished job runs eleven weeks instead of six. Had the second request been answered with "yes, and it moves us to week eight", the third would very likely never have been asked.