An ERP integration project should start with the business events you need to control, not with a connector catalogue. For a multi-channel business, orders, inventory, fulfilment, returns and financial transactions may move through several systems before the records are complete. The useful first step is to map those movements and decide which system owns each field.
1. Map the data before choosing the integration
List the systems involved in each channel: marketplace, Shopify store, warehouse or 3PL, ERP, accounting platform and reporting tools. For each important event, record where it starts, where it needs to go and which system is authoritative.
- Orders and cancellations
- Available and reserved inventory
- Shipments, tracking and delivery status
- Returns, refunds and adjustments
- Product and customer records where applicable
- Fees, revenue, taxes and cost information needed for finance
2. Decide how current each data flow needs to be
Not every process needs the same update frequency. Inventory exposed for sale may need frequent updates when stock is tight, while some finance and management reporting can work with scheduled batches. Define the acceptable delay for each flow based on the consequence of stale information rather than assuming everything must be real time.
3. Compare native connectors, middleware and custom integration
A pre-built connector can reduce implementation work when it supports the fields, countries and workflows you actually use. Middleware may help when several channels need a common integration layer. Custom API work can be appropriate when requirements are genuinely specific. Compare the supported objects, error handling, monitoring, rate limits, maintenance ownership and total operating cost—not just the initial implementation price.
4. Design the exception process
Integrations fail in ordinary ways: an SKU is missing, an order changes state, a return is partial, an API call is rejected or two systems disagree about inventory. Decide how errors are surfaced, who owns them and how a corrected transaction is replayed or reconciled. A silent integration failure is usually more damaging than a visible exception queue.
5. Test complete business scenarios
Before relying on the integration, test representative workflows from beginning to end. Include a normal order as well as cancellations, partial fulfilment, returns, refunds, stock adjustments and any country-specific processes you use. Confirm the result in the destination system rather than treating a successful API response as proof that the business record is correct.
6. Reconcile after launch
For an initial period, compare orders, inventory and financial totals between systems on a defined cadence. Record differences and determine whether they come from timing, mapping, configuration or an operating process. Keep ownership of the integration clear after the implementation project ends.
A practical starting document
Create a table with: business event, source system, destination system, required fields, expected update frequency, exception owner and reconciliation method. That becomes a more useful integration requirement than simply asking whether an ERP “connects to Amazon” or “connects to Shopify.”
If the challenge is broader than the connector itself, systems and reporting support can help map the requirements and operating handoffs before implementation.
Add reconciliation controls after go-live
For the first weeks, compare order counts, inventory movements, refunds and settlements between the ERP and each channel. Small mapping errors can create large downstream reporting problems if they are allowed to accumulate.
Maintain an integration ownership map
Record which vendor owns the connector, which team owns source data, who monitors failures and where incidents are logged. This prevents integration issues from bouncing between providers without resolution.