Interoperability refers to the ability of diverse systems and organizations to work together (inter-operate).
A process may be integrated with other requirements within a project, but may still not be interoperable with an external system or process. Interoperability requires standards and protocols to ensure both longevity and accessibility of data. [This could have an example of the longevity (and quality!) of the 8 track audio format but its lack of physical interoperability renders it practically useless – although the data is very safe!]