Change management: approval, CAB, impact analysis, backout plan, maintenance window

Change management is the formal process for proposing, approving, testing, implementing and documenting changes to systems. It matters for security because unplanned or poorly tested changes cause outages (an availability problem), open accidental holes such as a firewall rule left too broad, and make incidents harder to investigate because nobody knows what changed. A good process lets the organization change quickly and safely at the same time. SY0-701 treats change management as part of security operations, not just IT administration.