Web-Services als Basis für evolvierbare Softwaresysteme

Web-service-technologies are often regarded as the dominant way of software development in the future, especially for inter-company scenarios. While the current discussion in this area focuses mainly on the integration of software, this paper takes the next step and looks at the evolvability of the system resulting from the integration. A system’s adaptability in the face of changing requirements is usually the decisive success factor in industrial environments. This paper analyses experiences with a large, web-service-based application already in industrial use. As principal result we show that such a web-service-architecture indeed has the potential to support the evolvability of a complex software system. The clear separation of system components achieved by web-services — not only on a conceptual, but also on a technological and organizational level — is especially beneficial for large, long-term software projects that span company boundaries. The decision for a web-service-architecture requires additional efforts in the design, development and deployment of the software. With these additional efforts in mind, the concluding discussion offers some guidelines for web-service-projects, especially concerning the sensible (and economical) decomposition of the system into components connected by webservices. This contribution draws on experiences from a portal project for a large German company. The project employed around 50 persons including all sub- and partner-projects. For reasons of confidentiality the name of the company and project details are omitted, albeit without hurting the main points of the paper.