ABSTRACT
FIGURE 5.1: SOA vs. π-calculus. (a) SOA and (b) channel passing in π-calculus.
concepts investigated could all be represented using static process theory such as Petri nets or CSP [13,21].
With the rise of the Internet and service-oriented architectures (SOA) [10], however, the focus shifted away from static workflows that are executed in isolation. Instead, dynamic collaborations between different business partners moved into the center of attention. The key players in SOA are three entities. First, there exist so called service providers, which want to provide their services to customers. Second, service brokers allow service providers to register their-typically Web-services so that they can be found by the third kind of entity, service requesters. The whole setting is completely dynamic-service providers can (de)-register their services during the runtime of the system and service requesters can search for and bind to all currently available services.
