16. Migrate payment processors without a flag day

The brief

Own a 12-week migration from one payment processor to another. Produce an executable program plan with evidence-based go/no-go decisions rather than a list of meetings. No detailed service diagram is required if the dependency and decision flow is clear.

• Checkout, subscriptions, finance reconciliation, risk and support are owned by five different teams.
• New purchases can be routed gradually, but existing subscription tokens cannot all be transferred automatically.
• Finance closes books monthly. The legacy contract expires after week 12; a one-month extension is possible at a known extra cost.

Constraints

Initial program window≤ 12 weeks

Declare the initial implementation and rollout window; an extension must be a separately approved contingency.

Financial reconciliation

No cohort expands until payment, refund and settlement reconciliation is demonstrated with an owner and measurable gate.

Rollback boundary

Explain which transactions can be rerouted and which must be reconciled on the original processor.

Legacy subscriptions

Account for non-transferable tokens and any customer action without assuming token portability.

What to cover

1. 01

   Scope and success measures

   State measurable customer, financial and operational outcomes, plus explicit non-goals.

2. 02

   Dependencies and critical path

   Assign accountable roles and sequence token work, integration, finance validation, cohorts and support readiness.

3. 03

   Launch and rollback gates

   Define evidence, thresholds, decision owners and rollback boundaries for each cohort.

4. 04

   Risk and decision register

   Prioritize risks, give leading indicators and decision deadlines, and compare paying for an extension with accepting residual risk.

5. 05

   Week-eight intervention

   Assume reconciliation breaks for 0.4% of a pilot cohort in week eight. Explain containment, escalation and re-planning.

Worked designs

No worked design has been published for this brief yet. You can start an attempt and share your approach in the discussion.

Review rubric

AI feedback uses these criteria. Scores are practice feedback.