An ERP knows orders, stock and cost; it does not know what is happening on the shop floor right now. Production planning, quality or maintenance software fills that gap, but only if it talks to the ERP correctly. In integration projects the delay rarely comes from a protocol or an interface. It comes from a handful of questions nobody answered at the start.
1. Which system owns which data?
Item master, bill of materials, customer account, work order: each record type needs a single source system. If the same record can be changed in both systems, sooner or later nobody knows which one is right. The general rule is simple: master data lives in the ERP, and actuals from the floor live in the production system.
2. In which direction does data flow, and how often?
Write down the direction and frequency of every data flow. Orders and item masters flow from the ERP to the production system; production confirmations, scrap and consumption go the other way. Not everything has to be real time: the item master can be transferred once a night, while a production confirmation should reach the ERP within minutes.
3. How will the connection be made?
- Web service or API: if the ERP offers an official interface, this is the first choice; it causes the fewest problems at version upgrades.
- Reading through database views: a practical way to pull data only; not recommended for writing.
- File transfer: sometimes the only option with older systems; errors are hard to trace.
Writing straight into the ERP database looks fast in the short term, but it bypasses the ERP's own business rules and breaks at the next upgrade.
4. What happens when a transfer fails?
The network drops, the ERP goes down for maintenance, a record is rejected. What the integration does next has to be designed in advance: the record is queued, retried, and after a set number of attempts reported to a named person. An integration is not finished until there is a monitoring screen that shows which records did not go through.
5. Do codes and units match?
The same material may sit in the two systems under a different code, a different unit or a different warehouse definition. Mapping tables and unit conversions take more time than any other part of the project. Do this work before development starts, by cleaning up the master data.
6. Who maintains the integration when the ERP is upgraded?
When the ERP version changes, its interfaces may change too. The contract should say who maintains the integration, whether a test environment exists, and who tests before an upgrade.
Start small
Rather than switching on every flow at once, start with one: for example, the work order coming down from the ERP to the production system and the production confirmation going back. Once that flow runs reliably on the floor, add the stock, quality and maintenance flows.
Integration is not a job you do once and leave; it is a process that is monitored and maintained. An integration with no owner and no monitoring screen falls back to manual data entry at the first failure.