Data migration: why deltas make cutover easier

Data migration transfers the information your organisation needs from its existing systems into the new ERP. In a basic cutover, to ensure that all transactions and data changes make it to the new ERP, the source (live) system is frozen during the migration. This means the business stops. To avoid this, one option is to run the business off-system and key the records into the new ERP later, this is a huge effort even with semi-automated interim processes. Another option is: delta migrations.

Deltas enable the live system to keep running during the bulk migration – this dramatically reduces the freeze period. An initial load transfers the bulk of the data before cutover – the live system keeps running. Then, subsequent “delta” migrations apply only the changes from the live system since the previous successful load, including new and updated records, and relevant deletions. So ultimately the only freeze duration needed is the duration of the final delta, or ‘data top-up ‘. This can take a data freeze from days to minutes.

This means a shorter freeze and less (possibly no) business impact. However, it’s much easier to use deltas if you plan for them from the start -agreed in the data migration strategy. Trying to build and test delta migrations late in the day can cause many issues.