Interenterprise operability appears to be of high complexity with regard to technology, organisation, and application. It poses many challenges to supporting ICT solutions, frequently resumed under the term interoperability. A number of application issues have been pointed out in the Enterprise Interoperability Research Roadmap of the European Commission. The optimal organisational fit of ICT systems becomes a basic issue, as enterprise interoperability is always linked with business processes. And technological issues, in the end, put forward the question of software engineering, i.e. how to address the specifics of interenterprise processes by appropriate systems engineering approaches. This paper reflects on these issues and suggests to combine the concept of component based software engineering and the software product line approach, as a means to facilitate the engineering of adaptive interenterprise systems. We argue that such combination offers the potential of supporting interenterprise operability at a reasonable level of complexity, while keeping resulting systems adaptive and evolutionary.