In the old days, a couple of years ago, migrating data from one business application to another usually went like this:

1. A manual export from the source system to spreadsheets.

2. A tedious manual manipulation of the spreadsheet data in place, tedious manual copying and pasting from the export spreadsheets to import template spreadsheets, or both.

3. A manual import to the target system.

4. A fervent hope that nothing broke.

5. Repeating the process until it worked or the team gave up in exhaustion.