Paradigms of distributed software systems: Services, processes, and self-organization

State-of-the-art distributed software systems as well as applications as, e.g., e-commerce, e-business, e-services etc. are fundamentally based on the paradigm of distributed software or application services. Such services may already exist or may be newly developed for specific application purposes. They are able to interact — also in open and heterogeneous distributed environments — based on standardised interfaces and interconnection protocols as, e.g., provided by related “Web Services” standards. On the application side, advanced service-based software systems reflect (e.g. business) scenarios which are increasingly structured as sets of distributed co-operating entities. Such applications typically involve several and heterogeneous services from various sources — internally as well as from external sites. Further on, based on elementary services, more complex business processes or procedures help to realise more complex business semantics by composing services — even in dynamically changing environments — according to predefined (functional as well as non-functional) application needs. If, finally, such service become more and more “independent” and act “autonomously” (e.g. as “agents”) for achieving given goals and characteristics, services as well as business procedures should increasingly self-organise according to another actual distributed systems paradigm. The talk gives an overview of related problems, solutions, concepts, projects, implementations as well as some related standards.