Scope creep
Scope creep is the gradual growth of a project's scope without an explicit adjustment to resources, deadlines or agreements
What it means, how it is used and where it comes up, with its related concepts.
What it is and how it works
It usually appears when requests are added as if they had no impact. Managing it involves logging changes and assessing their effect before accepting them. Adapting a project may be necessary, provided the decision is conscious and shared.