TAFC to TAFJ Transition Checklist

1. Assuming customisations are well documented

They usually are not, and older local developments are often some of the highest-risk migration items.

2. Underestimating COB behaviour differences

Batch timing, sequencing, and restart expectations often need more deliberate testing than teams expect.

3. Treating interfaces as someone else's problem

Transitions often fail at the edges when file formats, schedules, or triggers shift slightly.

4. Knowledge concentrated in one or two people

If only one person truly understands the current state, the transition carries hidden operational fragility.

5. Testing only the happy path

Rollback, failure, and high-volume scenarios are routinely skipped even though reality tests them first.

6. Including operations teams too late

Support teams cannot safely own a target environment they have barely seen before go-live week.

7. Missing data quality problems until migration

Old assumptions and quiet data defects often surface under different processing behaviour in TAFJ.

8. Incomplete scheduler dependency mapping

Batch dependencies that were taken for granted can break or drift when not mapped explicitly.

9. Assuming vendor documentation is sufficient

Documentation explains product intent, not what fails at 2am under live operational pressure.

10. No realistic rollback plan

If the rollback decision framework has not been defined and rehearsed, the team is still exposed.

Before you start

• Why is the transition happening now?
• What outcome is actually expected?
• Who owns decisions across architecture, operations, and delivery?

Scope clarity

• Which environments are in scope?
• Which critical routines, versions, or interfaces need special handling?
• Is this full, phased, or hybrid migration?

Current-state assessment

• How does the estate actually run today?
• Which processes are most sensitive operationally?
• What workarounds are already hiding deeper issues?

Architecture and environments

• Are dependencies between application, middleware, database, and scheduling layers clear?
• Are environment differences understood?
• Are deployment and release processes already documented?

Customisation review

• Which local developments are business critical?
• Which custom routines are poorly documented?
• Which items rely on old assumptions that may not hold in TAFJ?

Interfaces and integrations

• Which upstream and downstream systems are operationally critical?
• Are file formats, schedules, and triggers fully understood?
• Has anyone mapped what breaks if a key integration fails?

Data and processing

• Are known data quality problems already documented?
• Are large-volume behaviours tested realistically?
• Are reconciliation and restart expectations clear?

Testing readiness

• Are business-critical flows covered?
• Are COB and batch behaviours tested properly?
• Are failure and rollback scenarios exercised?

Production support readiness

• Who supports the target state immediately after go-live?
• Are runbooks, monitoring, and alerting fit for purpose?
• Are escalation paths clear?

Operational readiness

• Are scheduler dependencies and recovery actions understood?
• Are access and permissions ready for support teams?
• Are post-go-live checks defined clearly?

Team readiness

• Do the right people understand both current and target state?
• Is knowledge too concentrated?
• Are responsibilities clear across project, BAU, infrastructure, and vendor teams?

Risk and go-live review

• What are the top five migration risks?
• What is least understood right now?
• Is the rollback decision framework genuinely clear?