Keep four stages of the switch distinct.

A working prototype does not establish that the team is ready to leave its workbook. Keep the decisions and evidence for discovery, building, switching and handover separately.

1. Before discovery: know the working source

• Name the workbook owner, daily users and the task that creates repeated work.
• List linked files, hidden calculations, macros, imports and exports. Identify the current version rather than collecting several unexplained copies.
• Prepare fictional ordinary and exceptional examples with expected results. Include a manual adjustment and the person authorized to approve it.
• Describe roles, devices and the first useful outcome. Mark estimates and unanswered questions as such.

Exit decision: the people explaining the workflow agree that the examples represent it. A provider should state what still needs investigation before estimating implementation.

2. Before building: approve the rules

• Agree identifiers, record relationships, required information and field ownership.
• Approve calculation examples and override rules; preserve the reason behind an exception.
• Define who may view, edit, approve and export. Include rejected actions and direct access to records.
• Choose behavior for competing edits, uncertain saves and repeated submissions. Keep important user work recoverable.

Exit decision: an ordinary user can explain the proposed journey, while the process owner can approve the expected outcomes. A prototype remains a review aid until its actual behavior has been implemented and checked.

3. Before switching: reconcile and choose the authority

• Rehearse imports in the agreed environment. Compare counts, identifiers, representative values, relationships and important reports.
• Record exclusions and differences, their owner and whether they block the switch.
• Have intended users complete the full task, including a correction, conflict and rejected action.
• Choose when the new application becomes authoritative and how old imports or workbook edits stop feeding conflicting values.
• Agree a protected recovery point, stop conditions, who decides to revert and the limits of that recovery.

Exit decision: the owner accepts the reconciled result and transition plan. A row-count match alone does not prove that the records mean the same thing.

4. At handover: leave an operable system

• Name business-rule, access, hosting and technical-support owners.
• Keep the accepted release, source, deployment and recovery guidance available through approved access.
• Explain routine corrections, backups, failed connections and the support route.
• Keep acceptance examples, known limitations and later improvements separate from the completed scope.

Exit decision: someone other than the builder can follow an agreed operating task using test data. Record open items with a next owner and review date, rather than calling the handover complete because documents exist.

Use these lists in your own controlled project notes; this page does not collect workbook data. Compare provider proposals, investigate a stale save or describe your first workflow.