Agree what belongs in the new system
List the record types to move and assign a business owner to each. Separate operational records from history that can remain in a read-only archive. Make explicit decisions about inactive products, duplicate contacts and open transactions before preparing import files.
Reconcile the meaning, not only the count
Equal row counts can hide incorrect values or broken relationships. Compare outstanding balances, stock quantities by location and links between documents. Sample normal records and exceptions such as credit notes or products with multiple units of measure.
Time the complete transition
Measure extraction, cleansing, loading, checks and sign-off. Document manual steps and identify which preparation can happen before the source system is frozen. The rehearsal should show whether the proposed cutover window is realistic.
Define the release decision
Agree tolerances and mandatory approvals before the rehearsal. Give every unresolved exception an owner and an impact assessment. Repeatable steps and reconciliation evidence are a more useful release signal than a green import screen.
Bring it to your next workshop
Choose one workflow, bring a representative data sample and involve the person who owns the business outcome.