Connecting an ERP to other systems: where to start

An ERP rarely shares all its data with every system. A sales application may send orders to it, a tracking tool may receive order status, and accounting may retrieve entries. Start by describing each exchange, its direction and its frequency.

Define the source of truth for each field

For a customer record, which system owns the address, VAT number or payment terms? If two systems can edit the same field, two-way synchronization may overwrite a recent correction. A simple rule for each field removes this ambiguity.

You also need a way to match records. One system’s internal ID may mean nothing to another. A mapping table or stable business identifier lets you update the correct record instead of creating a duplicate on each run.

Choose an exchange method that fits the systems

An API works when systems need frequent communication and expose suitable interfaces. File imports can be enough for a daily job or software without an API. The choice depends on actual system capabilities, volume, acceptable delay and how errors will be handled.

Before building, ask these questions for each flow:

• What triggers an exchange: an action, a schedule or a request from the other system?
• Which fields are required, and what transformations are needed?
• What happens if the receiving system is unavailable or rejects a record?

Plan checks and recovery

A successful API call does not prove that all expected data arrived. Monitoring should show processed volumes, rejected records and the latest successful synchronization. For scheduled jobs, storing progress helps resume after an interruption without creating duplicates.

Test common edge cases too: an order changed after its first transfer, an existing customer, a missing required field or a restarted import. Once the flow is live, someone needs to know where to see errors and how to retry corrected records.

Start with one useful, testable flow

A limited first scope lets you validate business rules and data quality before adding more connections. Describe the desired outcome using real records, anonymized where necessary. That gives you a clear basis for estimating and building the integration.