6.4 Compatibility measures

What this heading covers

Co-existence is about sharing resources without harm: memory, ports, files, device access, scheduling. Interoperability is about exchanging and using information correctly. The two are often measured as one compatibility percentage, which hides the difference between a product that runs beside another and a product that talks to it. The environment list is part of the measure: a co-existence result without the other products and their versions is not reproducible, and an interoperability result without the interface and the message set is not either.

Record position: characteristic 3 of 9, carrying 2 of the 40 measure families in clause 6.

What the heading asks of a team

The common confusion

Compatibility is often read as a list of supported platforms. Co-existence is about sharing an environment without harm; interoperability is about exchanging and using information. A platform list answers neither.

The measure families in this characteristic

• 6.4.2 Co-existence measures
• 6.4.3 Interoperability measures

What to put in place before publication

1. List the products and versions the product is expected to co-exist with, and the resources they share.
2. List the interfaces and message sets the interoperability measure covers, with their versions.
3. Define what counts as a conflict and what counts as a failed exchange, so the two families stay apart.
4. Record the environment for every result, including the operating system and the runtime.
5. Review the lists at every release, because compatibility is a moving target.

Where teams usually fall short

• One compatibility score that mixes a port conflict with a failed data exchange.
• An interoperability test run against a mock that no longer matches the live interface.

What happens next

Co-existence is the smaller family and the one that bites in a shared desktop or a shared cluster. Interoperability is the one a procurement team will ask about.