Establish data ownership before synchronization

When two systems can change the same information, a technical field mapping is insufficient. Without business rules, synchronization can overwrite current values or send changes back and forth between systems.

Record decisions for each data area

• Identify the authoritative system for master data and individual status information.
• Define shared identifiers and how unknown records are handled.
• Describe conflicts, deletions and retrospective corrections explicitly.
• Present exceptions in a form the responsible business team can resolve.

For a customer account, one system might own the postal address while another owns the contract status. Authority then applies to each data area rather than the entire record. Timestamps alone do not resolve that distinction.

Walk through realistic change scenarios before connecting additional systems. Include a delayed message: a technically valid older state should not silently replace a newer business state.