What is a Change Management Plan?
The change management plan defines how changes will be handled before any change exists: who may submit requests, how impacts get assessed, who approves at which thresholds, and how approved changes flow into baselines and communication. It's the rulebook that makes change control fast because it's predictable.
Don't confuse it with organizational change management (preparing people to adopt outcomes) — same words, different discipline; scenarios test whether you know which one is being described.
Worked example
A rail project's plan sets three lanes: field changes under $25K — engineer approves within 48 hours; up to $250K — change board, weekly; above that or any schedule impact — steering committee. When a drainage redesign lands at $80K, nobody invents a process or waits for a committee that meets quarterly. The lane already existed; the change moves at the speed of the rulebook.