Deriving services from KAOS models.

Designing software using a SOA (Service-Oriented Architecture) style requires systematic service development approaches. In contexts where such style is used, business objectives can be described using goal models, such as those used in requirements engineering. A goal-based requirements specification should ensure completeness of the goals to be achieved, as well as their temporal and logical dependencies. Currently, existing service-oriented approaches do not offer systematic methods for service identification, and the principles and guidelines proposed are very difficult to follow in practice. This makes service identification a challenging task, requiring skilled experts to identify services and their characteristics. This paper offers KAOS4Services, a systematic approach to derive services from goal-models expressed using the KAOS language. This is achieved with model-driven techniques and a set of heuristics applied to goal-models. The result is a reference architecture with a list of candidate services. A case study demonstrates how our method guides the service designer during the identification of a set of the services composing the SOA specification.