Inventory the legacy landscape
Document applications, databases, file exchanges, machine interfaces, ownership, support status and business processes before designing replacement flows.
Use controlled interfaces
APIs, database views, messaging adapters or file gateways can isolate MES from legacy-specific formats. Direct database writing should be avoided unless it is an explicitly supported contract.
Replace by capability
A staged approach can move one business capability at a time—such as genealogy or dispatch—while the old system continues other functions during transition.
Operational risk
Unsupported software, unknown credentials and undocumented interfaces should be treated as project risks. Integration does not remove the underlying lifecycle risk.
MES terminology and boundaries vary among plants and vendors. Validate data ownership, safety impacts, interfaces and change control against your actual manufacturing architecture and approved procedures.