Formal Description of Component Services

Usability of a software component affects the efficiency of component based software development directly, but how to improve it is still an open issue due to the separation-of-concern development pattern adopted by component-based development (CBD) in software engineering. From the provider´s point of view, first of all, atomic service and service extension are defined respectively, and extension rules of a component service are given in detail. Secondly, service logical and reasoning system, a formal description method, is proposed to describe all services which a common interface can provide. Thirdly, the process of service constructed by using atomic service extension is given and illustrated by an application sample. And finally, the analysis of a concrete sample shows that the formal description method can provide a valid verification approach which can automatically determine whether it satisfy user´s requirement or not. This approach can help improve the usability of a software component and also contribute to the automatic process of component based software development.