Twenty-seven working days from kick-off to go-live, then thirty days of coaching. Count working days, not calendar days: load the customer’s public holidays into the Project Plans workbook’s Setup sheet, and every task date is calculated from its T-day.
Pre-flight: before the clock starts
T-27 is day one of the countdown, not day one of the relationship. Four kinds of thing must already be true:
- Commercial — contract signed and audited revenue received; the go-live date on the board; the scope anchor (modules and entities for wave 1).
- People — a Countdown Owner with same-day scope authority; a TRANXACT Flight Lead; a key user per process, named and released for the countdown.
- Tenant — the onboarding form submitted; the tenant provisioned on its three-node cluster; key users able to log in.
- Data — read access to every legacy source; representative sample data extracted; a cutover date and migration scope (as-of / period) proposed.
How this meets the Technical Deployment Guide: its proposed build targets — onboarding form, design sign-off and a build from code of about five working days each, five more with Live DR — run before T-27. The countdown assumes the environment exists, which is why the tenant is a pre-flight item and T-Minus has no landscape-build milestone.
Five stages, each with an exit
| Stage | Exit criterion | Leaves behind |
|---|---|---|
| Discover by doing · T-27 → T-18 | Every Fit Ledger line tagged; wave 1 signed by the Countdown Owner | Fit Ledger, draft object register, migration scope, change impact, comms plan, RAID log |
| Configure in the open · T-17 → T-11 | Every Configure-now line configured and checked | Configuration Workbook, readiness register, Test Plan, M1 mapping signed |
| Cutover, audited · T-10 → T-3 | Zero TB delta on the dry run with audit trail; the dry run fits the window | Reconciliations, Cutover Runbook with timings, Rehearsal Script, defect log |
| The Rehearsal · T-2 → T-1 | The rehearsal passes — the only go / no-go | Rehearsal results, Go / No-Go record, participation per user, final cutover plan |
| Go-live · T-0 | The first invoice posted in production, usually before lunch | Final runbook column, signed reconciliation, Hypercare Exception Log, first KPI |
| Coach in the flow · T+1 → T+30 | Exceptions trending to zero; hypercare absorbed | Hypercare log, T-Plus backlog and wave plan, KPI Scorecard |
One go / no-go, and facts for everything else
Countdown start (T-27), scope freeze (T-18), configuration complete (T-11), reconciled dry run (T-3), go-live confirmed (T-0) and hypercare exit (by T+30) are each a checkable fact with evidence attached in the Toolkit’s Go-No-Go Gate sheet. Only the rehearsal at T-1 is a decision. Auditors and the steering sponsor read the evidence, not a status report.
Six workstreams against one clock
Core implementation, data migration, testing, adoption and training, change management, and technical and integration all run in parallel. In Cutover, audited, for instance: configuration fixes only; M1, M2, the dry run and reconciliation; migration validation and role tests; users on rehearsal data; a readiness pulse; endpoints tested and a DR drill. The Project Plans workbook tags every task with its workstream, so each lead filters their own view.
Waves, never longer phases
A larger deployment repeats the 27-day countdown on the same ledger: wave 1 the core entity (Accounting, CRM, Supply Chain), wave 2 further entities and HRMS, wave 3 Manufacturing, EHR or Student Lifecycle, wave n deferred Fit Ledger scope and new regions. Each wave toggles modules and entities on; growth never triggers a re-implementation.
Treat any unticked pre-flight item as a reason not to start the clock. Without them the first days are spent chasing access instead of discovering by doing.
Calderwood’s Flight Lead finds at pre-flight that its legacy ERP can only be extracted by the vendor’s support desk. That party is booked for M1, M2, the dry run and T-0 before the clock starts — not discovered at T-10.
Try it It is T-18. Calderwood’s Fit Ledger has 64 lines, but three are still untagged because the finance controller is on leave. Can the scope-freeze gate pass?
No. Scope freeze requires every line tagged and wave 1 signed by the Countdown Owner. The fix is not to wait: the Countdown Owner, who has same-day authority, makes the three calls in today’s standup — configure now, T-Plus or not needed — and signs. A controller’s view can still be sought, but the gate is a fact, and it is the Countdown Owner’s to close.