05Cutover, Change Management & Legacy Deprecation

I land the change, retire the old, and own what comes after.

Transitioning the reporting user base, turning off legacy infrastructure, and controlling cloud cost creep — go-live was never the finish line for me. Adoption was.

Change management

Change Management & Regional User Enablement

I never treat this as end-of-project training bolted onto the schedule. It starts at mobilization and runs the whole length of the program, because thousands of people have to trust the new numbers, not just get handed a login.

Why this artifact

"We'll train people before go-live" isn't a plan, it's a hope. Staging awareness, involvement, training, and adoption as distinct tracked stages is what lets me catch that Sales is behind on champion recruitment two months out, not two weeks out.

Artifact · Adoption planawareness → adoption
StageWhenWhat I ranMeasured by
AwarenessMobilizeComms on the why; impact broken out by functionReach
InvolvementDesign → UATSMEs pulled into mapping and parity sign-off; champions recruited per functionSME participation
TrainingPre-cutoverRole-based training; office hours; quick-reference guidesCompletion %
AdoptionPost go-liveChampions support; usage nudges; feedback loopActive users vs. target

Adoption at scale

I recruited a champions network inside every function, one per business unit, and tracked usage against a target instead of assuming adoption would just happen because the platform was live.

4 wks
Users I migrated
94%
Active on new platform · wk 6
8
Function champion pods I ran

Retire the old, own the cost

Legacy Decommissioning & Cost Realization

I don't switch off the SQL Server EDW on a date from the plan — I switch it off against criteria I set. A defined confidence window, adoption holding, and zero reconciliation gaps, before I signed off.

Artifact · Decommission gatemy criteria
CriterionStatus
Confidence window elapsed with no reconciliation gapsMet
Adoption steady above targetMet
No dependency still reading legacyMet
Archive & retention captured for complianceMet

Closing the program against my own baseline

Artifact · Closeoutplan vs. delivered
DimensionBaselineActualResult
Scope250 reports, 8 functions250 deliveredMet
Schedule~9 months+2 weeks (Wave 3 SME slip)Within tolerance
BudgetApproved baselineOn budgetMet
Financial parityZero-defect reconciliationZero variance at go-liveMet
BenefitLegacy retired; TCO reducedDecommissioned; scope cut 38% via my rationalizationRealized

The judgment call

What I decide here

What I Decide Here

Decision: Post-cutover, I find power users running unoptimized legacy-style SQL that's causing cost spikes. I set auto-suspend timeouts on the virtual warehouses and enforce a mandatory 15-minute optimization check for anyone running heavy queries.

Friction: Analysts complain about queries getting cut off during initial testing — cloud-native query discipline isn't a habit yet, and it shows.

Outcome: It cuts compute overruns in the first month, and shifts query culture toward cloud-native habits instead of just tolerating the old bad ones on a new bill.

What I'd tell the next TPM

Retrospective

Why this artifact

A program that closes without a written retro just repeats its mistakes on the next one, with a different TPM re-learning them the hard way. Writing down the SME-booking miss is what makes it a lesson instead of a grudge.

Artifact · Retroroot cause · action

What worked

Rationalizing first cut 38% of scope before I let anyone write a line of code. Daily dual-run reconciliation meant cutover held no surprises. Naming a business owner per field turned definition fights into decisions I could point back to.

What I'd change

I didn't book SME time far enough ahead — the one schedule slip I took traced straight back to it. Action for next time: 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 my proof point for the whole program: 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.