t of view of the service itself. It is an abstracted version of the original service. An operating guideline of a service represents the possible communication behaviours of partners of the service. It is comparable to user instructions shipped with real-world devices. Both public views and operating guidelines support a number of scenarios, in particular service discovery. We propose algorithms for computing public views and operating guidelines. Exchanging Services A company may wish to exchange one of its services for another that is better suited for some purposes. The exchanged service should mimic all the interaction capabilities with existing partners. We differentiate between exchange at design time and exchange at run time. While exchange at design time concerns only new instances of a service, exchange at run time takes care of migrating instances of a service that are already running. As a particular scenario of exchangeability, we study contract-based compositions of servic...