How to leave an old ERP without losing a single order
A six-step, side-by-side approach for manufacturers replacing a long-running ERP such as Global Shop, Epicor or JobBOSS, plus a checklist of questions to ask any vendor.
Every manufacturer who has run the same ERP for 15 or 20 years has the same fear about replacing it: the day you switch, something breaks, orders get lost, and the floor stops.
That fear is reasonable. Most failed ERP projects don't fail because the new software is bad. They fail at the cutover, when a company stops using the old system on a fixed date and trusts that the new one was set up correctly.
Here is the approach we use instead.
1. Start from your exports, not a blank form
Your old system already holds years of decisions: item numbers, bills of materials, customer and vendor terms, pricing. Retyping that invites errors. Start from the old system's own exports, so nothing is invented and nothing is forgotten.
2. Map every field, and have your people approve it
Field mapping is where quiet errors hide: a unit of measure that means "each" in one table and "box of 10" in another, or a customer type nobody has used since 2011. Software, including AI, can draft the mapping quickly, but the people who know the data should approve every field before anything moves.
3. Treat imported records as evidence, not decisions
An imported open order should never become a live order, invoice or accounting entry on its own. Someone should look at it and decide, and every change should be logged so you can see who decided what.
4. Run old and new side by side on real work
For a period, enter real orders, purchases and receipts in both systems. It is extra work, and it is the best insurance you can buy.
5. Compare the numbers, and explain every difference
Compare open orders, on-hand quantities, inventory value and open purchase orders. Where the numbers don't match, find out why. Usually it is a rounding rule, a date typed as 01/01/00, or a tolerance the old system never enforced. Fix it, then compare again.
6. Switch when your team signs off, not on a date
The go-live date should follow the evidence. When the people who run production, purchasing and accounting agree the numbers match, you switch. Not before.
A checklist to take into any ERP project
- Who approves the field mapping, by name?
- How long will both systems run side by side?
- Which reports will we compare, and who signs off on each?
- What happens to imported records before they go live?
- Can we see a log of every change made during migration?
If a vendor can't answer those clearly, the risk sits with you.
Frequently asked questions
How long should old and new systems run side by side?
Long enough to cover a full cycle of your business: orders through shipping and invoicing, purchasing through receiving, and at least one month-end. The exact length depends on your volume and is agreed before the project starts.
What data can be moved from Global Shop?
Typically items, bills of materials, customers, vendors and pricing come across from exports. Open orders, routings and history are scoped case by case during an assessment.
Can AI do the migration for us?
AI is good at drafting field mappings and spotting inconsistencies quickly. The decisions should stay with the people who know the data, and nothing imported should go live without review.