On the Concept of Service Coordination

In this research report we study service coordination, which is a crucial aspect when services are combined into service-based systems (Metzger & Pohl, 2009).Coordination is not only in computer science an important research topic. It is also studied in disciplines such as organization theory, operations research, economics, linguistics, and psychology. Malone & Crowston (1994) studied the similarities and connections between the different flavors of coordination and created a more generic coordination theory. They define coordination as managing dependencies between activities. This definition is based on the intuitive idea that there is nothing to coordinate without any interdependence. In their work they state that coordination theories should try to characterize different kinds of dependencies and identify the coordination processes that can be used to manage them. Therefore, in the next section (see Section 2), we will discuss several types of dependencies that can exist when composing services to service-based systems. In the rest of this research report is targeted at two types of dependencies, namely sequence dependencies and data dependencies. Therefore, the research continues in Sections 3 and 4 with an overview of existing techniques for managing sequence and data dependencies, respectively. In each section there is also a general conclusion included.