Identifying Potential Core Assets in Service-Based Systems to Support the Transition to Service-Oriented Product Lines

Variability in service-oriented architectures (SOA) is usually addressed through loose coupling of services and dynamic retrieval, composition and binding of services. Facilitating variability can lead to different instances of one SOA. These instances share commonalities, but vary in certain aspects (e.g., in functionality or quality attributes). Current service-based development approaches do not adequately address variability and the management of different SOA instances. To handle different instances and to support systematic variability management, different instances of a service-based system may be treated as members of a product line. Therefore, we present a light-weight method to decide on what services to add to service-based systems to facilitate the transition from individual systems to a service-oriented product line. When adding services to service-based systems, the structural stability of these system decreases. We argue that a decrease in structural stability must be justified by additional value provided by the enhanced service-based systems. Based on the enhanced systems, our method then identifies potential core asset services for a service-oriented product line, taking into account common services within the different systems. Here, core asset services are reusable services that occur in any instance of the SOA. Thus, our method helps with the transition from individual products to a product line. A case study is included to illustrate our method.