Dual Run and Cutover
Track the cost of parallel estates and separate cutover from financial exit.
Dual run occurs when a workload's source environment and AWS target operate at the same time. It creates genuine transition exposure that can persist long after the user-facing system has switched.
Planned versus actual overlap
Record the planned overlap window, actual source/target states and available costs. Compare planned dates with actual observations, and distinguish imported source run rate from observed target AWS billing.
Cutover event
A cutover records the technical handoff to the target environment. The event may include an actual date, actor and notes. Repeated submission for the same successful cutover should be idempotent; conflicting re-completion needs explicit review.
Important
After cutover
Check whether source costs decrease as expected. Watch for overrun days and residual financial commitments. Send the workload to decommission tracking instead of assuming the old estate was retired automatically.
Common mistake
Calling projected AWS operating savings “realized” at cutover is premature. The Value Ledger needs the appropriate post-change evidence and verification path.