Migration Planning: Prove a Small Slice Before Moving Everything
Define source-to-target checks, permission tests, and recovery criteria for a staged migration exercise.
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Inventory dependencies before copying data
Identify source tables, transformations, refresh schedules, report consumers, service identities, and downstream exports. Record which source remains authoritative during transition. A migration is incomplete when data arrives in the target but the report definition, access restrictions, or recovery process changes without review.
Work through a narrow slice
Choose a small reporting scenario, such as one month's sales by region. Preserve a stable source snapshot. Compare the source and target row counts, unique transaction keys, null handling, date boundaries, and total amounts. If the source total is 1,000 and the target is 980, investigate the missing 20 instead of dismissing the difference as a refresh delay. This example is fictional and supplies a reconciliation question, not a measured migration result.
Test more than totals
Verify permissions using reader and editor identities. Test incremental updates, late corrections, deletes, duplicate imports, and an interrupted run. Confirm that refresh timing and dependent exports still satisfy the agreed business requirements. A successful administrator demonstration cannot substitute for the consuming user's experience.
Plan the handover
Write cutover criteria, an owner for each failed check, and a recovery path before moving production users. Document what can be reversed, what data must be replayed, and how changes made during the transition are reconciled. Retain the source for the agreed validation period rather than deleting it immediately. Compare actual workload behavior and total cost after the pilot; do not assume a platform change by itself guarantees faster reports, lower costs, or compatibility with every legacy feature.