238,945 records. Twenty-seven years. None lost.

A professional services firm with twenty-seven years of client history was moving off a system it had outgrown. Every client the firm had ever worked with, every matter, every contact and every note lived there, 238,945 records in total, entered by dozens of people over three decades with no shared convention for how a name or a company should be written.

The firm's risk was specific. A migration that lost even a small fraction of those records would lose relationships the partners could not reconstruct, and a migration that moved everything without cleaning it would fill the new system with the same duplicates and blanks that had made the old one hard to trust.

The export came first, in full, before anything else was touched, so there was always a copy of the firm as it stood. Every record was then mapped field by field to the new system, with the fields that had no home in the destination written down and decided on with the partners before the load.

The load ran in stages, with a count at the end of each one reconciled against the export. Where the counts disagreed, the load stopped until they agreed. The 45,842 contacts were loaded with their full history attached, and after activation three real records were opened by name and checked line by line against the original before the migration was called complete.

The count at the end matched the count at the start. 238,945 records in the new system, each traceable to its original.

Every relationship now has one record, with its full history attached, that anyone at the firm can open by name. Before the migration, that was a search across two systems and a person who remembered.

The firm's second engagement with CWT, an automation that keeps new records to the standard the migration set, was signed within two months of the migration closing.

Migrations fail at the count. A firm that has a count before, a count after, and a reconciliation between them does not lose records. A firm that has a reason to trust the new system starts using it. The two are the same discipline.