Deciding how much history is worth carrying across
The opening request is almost always to bring everything, and it is almost never the right answer. Full transactional history enlarges the scope, extends the load window on the weekend when time is scarcest, imports years of inconsistent coding into a clean system, and slows daily work in return for records that will be queried a handful of times. It also embeds old problems into a system whose main selling point was supposed to be a fresh start.
A better shape is usually straightforward. Open items and balances go into the ERP, where they are needed for daily operation. History goes into a read only archive that is indexed, searchable and available to the people who need it, with a retention decision attached and a stated cut off date. Prove the archive can still be read after a version upgrade, because an unreadable archive is functionally identical to no archive on the day somebody finally asks for it.
Settle the argument with usage rather than sentiment. How often was history actually consulted in the past year, by whom, and would a report have answered the question. Most organisations discover the answer is narrower than the request implied. One boundary applies throughout. Legal and tax retention obligations are not ours to determine. The client's advisers set the period and the form, and we design the archive and the extract to satisfy what they specify rather than interpreting the requirement ourselves.
- Open items and balances migrated, with closed history archived rather than loaded
- A read only archive that is indexed, searchable and proven readable after an upgrade
- Retention decisions attached to each data set and sourced from the client's own advisers
- Actual query frequency measured before agreeing how many years of history to carry
- A written cut off date, published to the business before extraction begins