Service functionality and behavior

One of the most essential parts of every service description language is to provide suitable means for describing the following three aspects of services: (1) what the service does, i.e., which functionality it provides, (2) where the service resides, i.e., where it can be accessed and via which means it can be consumed, and (3) how the service behaves, i.e., how to interact with the service in order to properly consume it. These are subject to various existing and well established standards. In order to capture these aspects in an all-embracing manner, USDL defines three separate modules - the Functional, the Technical, and the Interaction Module - that each cover one aspect and together provide a holistic description of the functionality and behavior of services. The modules are commonly designed to provide a unifying description structure that abstracts from details and allows for the re-use and integration of existing as well as upcoming standards, thereby maintaining flexibility and extensibility of USDL. This chapter introduces the background and underlying design principles, and presents the USDL modules for functional, technical, and behavioral service descriptions in detail.