Bilateral Data Flow Definition
A Bilateral Data Flow is a two-directional integration in which data moves between two systems in both directions, with each system capable of sending updates to the other. Changes made in either system are propagated to its counterpart according to defined synchronisation rules.
Common examples
A CRM and an ERP exchanging customer records bilaterally: the CRM owns contact details and pushes updates to the ERP, while the ERP owns payment status and pushes that back to the CRM. In a Master Data Management context, a bilateral flow might exist between an MDM platform and a PIM, where the MDM provides the golden record as a base and the PIM returns enriched marketing content that is then written back into the master record.
Why does it require more governance?
Bilateral flows introduce the risk of update conflicts, both systems modify the same field before either change is synchronised, and the integration must decide which value wins. This requires explicit conflict resolution rules, clear data ownership per attribute, and robust logging to keep data lineage traceable. Without these controls, bilateral integration can produce circular overwrites where systems repeatedly undo each other's changes. For this reason, bilateral flows are typically scoped narrowly: each attribute should have one designated system of record, even when the overall integration runs in both directions.