Ideally you should be getting less variation on outgoing interfaces compared to incoming interfaces. See HL7 Interface Specification and Contract.

For validating outgoing interfaces, a process will be required, similar to the one below:

• There should be a sample of a few hundred HL7 messages in the format expected by that site - i.e. the expected output.

• There should be a simple way of populating your application's database with a set of test data to produce that expected output - i.e. the standard input.

• The resulting output can be compared to the expected output using the msgdiff tool.

As the application grows and improves the standard input may change - but the structure of the expected output should be the same. The software implemented by the Primary Integration Engineer should support this quality assurance process.