How do you handle change management in enterprise engagements?

Formal change control adapted to your existing process. Most enterprise clients have established change management procedures (CAB approvals, written change requests, scheduled deployment windows, post change validation) and we slot into those rather than imposing our own. For clients without an established process we use a structured change template: written change request, technical review, security review, business approval, deployment plan, rollback plan, post deployment validation. Emergency changes follow a separate fast track process with retrospective approval.