Dynamic requirements specification for adaptable and open service-oriented systems

It is not feasible to engineer requirements for adaptable and open service-oriented systems (AOSS) by specifying stakeholders' expectations in detail during system development. Openness and adaptability allow new services to appear at runtime so that ways in, and degrees to which the initial functional and nonfunctional requirements will be satisfied may vary at runtime. To remain relevant after deployment, the initial requirements specification ought to be continually updated to reflect such variation. Depending on the frequency of updates, this paper separates the requirements engineering (RE) of AOSS onto the RE for: individual services (Service RE), service coordination mechanisms (Coordination RE), and quality parameters and constraints guiding service composition (Client RE). To assist existing RE methodologies in dealing with Client RE, the Dynamic Requirements Adaptation Method (DRAM) is proposed. DRAM updates a requirements specification at runtime to reflect change due to adaptability and openness.