The Interoperability Special Interest Group met from 9 am till 10 am European Central Time on November 27, 2017.


How to distribute an extended IDL


Malcolm WOODMAN (MRWConsult), Michael HALLORAN (CO-LaN), Michel PONS (CO-LaN)


The conference call was dedicated entirely to versioning within the CAPE-OPEN standard since new interface specifications (Flowsheet Monitoring for instance), or revision of existing ones (Petroleum Fractions for example) are close to finalization and hence release. The issue to address is how to distribute whatever needs a software developer with respect to these new or revised interface specifications. The Interoperability SIG is tasked with distributing CAPE-OPEN Type Libraries and Primary Interop Assemblies. Discussion was already started at the previous conference call.

Current thinking of the Interoperability SIG is that each interface specification document should follow its own development and maintenance life, i.e. have its own, independent versioning. For example Flowsheet Monitoring should be at version 1 when released for the first time.

Each documentation set carries a version number and the contents of a documentation set must be detailed. Documents within a documentation set carry their own version number which is not linked to the version number of the documentation set.

The text in each interface specification document should not mention to which documentation set the document belongs since the version of the documentation set will evolved.

The CapeVersion key is not well defined in the Methods & Tools integrated guidelines. It has been used so far to reflect what was understood as the CAPE-OPEN standard version number to which a given Process Modelling Component is adhering. It is recommended that it reflects rather the version of the interface specification document it is adhering to. Hence for Flowsheet Monitoring it should be with a major number of 1.

The participants have agreed to progress on the definition of a strategy and of rules on versioning by exchanging offline. The next conference call of the Interoperability SIG is scheduled for January 12, 2018.


Any CO-LaN member with interest in the development of the set of software tools offered by CO-LaN is welcome to join. Please contact Malcolm WOODMAN, leader of the SIG ( for further information.