Go-live isn't the finish line — adoption is. The program only closes once thousands of users are actually working in the new platform, the legacy EDW is safely decommissioned, and the lessons are written down for the next migration.
Change lands here
The change-management investment made since mobilization pays out now: role-based training, a champions network inside each function, office hours, and usage tracked against a target so adoption is managed, not assumed.
Retire the old
The SQL Server EDW is switched off only after a confidence window — a defined period where the new platform runs alone, adoption holds, and no reconciliation gaps appear. Decommission is a decision with criteria, not a date on a plan.
| Criterion | Status |
|---|---|
| Confidence window elapsed with no reconciliation gaps | Met |
| Adoption steady above target | Met |
| No dependency still reading legacy | Met |
| Archive & retention captured for compliance | Met |
Baseline vs. actual
| Dimension | Baseline | Actual | Result |
|---|---|---|---|
| Scope | 250 reports, 8 functions | 250 delivered | Met |
| Schedule | ~9 months | +2 weeks (Wave 3 SME slip) | Within tolerance |
| Budget | Approved baseline | On budget | Met |
| Financial parity | Zero-defect reconciliation | Zero variance at go-live | Met |
| Benefit | Legacy retired; TCO reduced | Decommissioned; scope cut 38% via rationalization | Realized |
What we'd tell the next team
Rationalizing first cut 38% of scope before a line was built. Daily dual-run reconciliation meant cutover held no surprises. Naming a business owner per field turned definition fights into logged decisions.
SME time wasn't booked far enough ahead — the one schedule slip traced straight to it. Action: reserve SME capacity per wave at planning, not at UAT.
Golden thread · closed
The close-amount field that surfaced a 6% variance in test became the program's proof point: the reconciliation strategy did its job, the definition got fixed by the business, and go-live reconciled to the penny. The whole migration in one field.