The big-bang cutover has a failure rate that should terrify any IT leader who has proposed one. Five concrete reasons:
- The surface area is too large to test completely before a single go-live date.
- The fallback is never as clean as promised ā the database has usually diverged.
- Defects surface months after go-live, not on day one.
- Organizational pressure suppresses the signal when a date has been announced.
- Without parallel running, there is no systematic proof the new system is correct.
The alternative: module-by-module migration with formal parallel running, legacy as the source of truth throughout, a rolling cutover that never bets everything on a single night.
It takes longer to plan. It takes far less time to fix.
You can find relevant information in the specific section: https://enable-dev.com/modernization
Follow us on LinkedIn.
