An ERP rarely works alone. Orders arrive from e-commerce, bank files go out and come back, payroll posts summaries, and data flows to CRM and reporting tools. When integrations are designed as an afterthought, they become the most fragile part of the system. This guide sets out the architecture and monitoring practices we use for Dynamics 365 Business Central and Finance and Supply Chain Management.
Start with an integration inventory
For every interface, record:
- Source and target system, and which one owns each piece of data.
- What triggers it: a schedule, an event, or a user action.
- Volume and timing: how many records, how often, and how quickly they must arrive.
- What happens when it fails, and who needs to know.
This inventory becomes the design document and later the support runbook.
Choose the right pattern
- APIs (request and response): suitable for real-time lookups and low to moderate volumes. Business Central offers standard REST APIs; Finance and Supply Chain Management offers OData services.
- Event-driven: the ERP raises a business event (for example, an invoice posted) and subscribers react. Both products support business events, which avoids constant polling.
- Batch and file-based: suitable for high volumes and partners who work with files, such as banks. Finance and Supply Chain Management's data management framework and recurring integrations are designed for this.
- Low-code automation: Power Automate works well for simple, lower-volume flows between Microsoft 365 and Dynamics.
Avoid direct database integrations. They are not supported in the cloud and break when the data model changes.
Design for failure
Every integration will fail at some point. Plan for it:
- Retries with sensible limits for temporary errors such as timeouts.
- Idempotency: sending the same message twice must not create two invoices. Use unique external references and check them.
- Dead-letter handling: messages that can't be processed are parked with a reason, not lost.
- Ordering: decide whether the order of messages matters, for example creating a customer before its first order.
Audit and reconciliation
- Log every message with a timestamp, status and reference.
- Reconcile totals between systems daily for financial integrations: count and value of orders, invoices or payments.
- Keep enough detail to answer "did this record arrive, and when?" without a developer.
Security
- Use service accounts or app registrations with the minimum permissions needed.
- Store secrets in a secure vault, never in code or configuration files.
- Rotate credentials on a schedule and when people leave.
- Review which external systems can write to the ERP.
Monitoring
- A dashboard or list showing each integration's last successful run and failure count.
- Alerts to a shared mailbox or team channel, not a single person.
- A named owner for each integration in the support model.
Build or buy?
Standard connectors and proven apps are usually cheaper to own than custom integrations. Our Xero Bills Connector is an example of a packaged integration with status tracking built in. Where no product fits, our Business Integrations service builds connectors on demand for your systems, following the principles above.
Next step
If your integrations break more often than they should, request an integration assessment. See also our ERP data migration controls guide, which uses many of the same reconciliation ideas.