The MDIS communication link shall be verified between the SPCS and DCS. Testing shall include both normal operation and failure scenarios. Redundancy and performance requirements should be tested under full load (i.e. shutdown conditions). Time synchronisation should be verified.

Clients and Servers that have passed independent MDIS certification should require less integration testing. Integration testing should be focused on the project configuration rather than base MDIS functionality. It is recommended prior to any integration testing that the interface specification, defined in Section C.6 and OPC UA UANodeSet files be finalised and agreed between SPCS and DCS vendors as early as possible. Integration testing should only be attempted when the SPCS and DCS software has reached an acceptable level of maturity.

It is recommended that, during project execution, preliminary integration testing be performed to validate the data exchange across the MDIS Interface off critical path, prior to full onsite integration testing. In addition to validating data exchange, this testing should allow for verification of graphical displays, redundancy and data prioritisation. Validation of performance and full functionality, including shutdowns, sequences and interlocks, should be performed during full onsite integration testing using the hardware that will be supplied to the project.