New specification environment for communication systems based on specification reuse by the application of case based reasoning

To advance the productivity of software for communication systems, specification development is important as well as the implementation of the software. For this reason, we developed a specification description language HSC (Hierarchical Sequence Chart), which is useful during the early stage of specification development. The features of HSC are: a) HSC is suitable for a top-down style of specification development, b) specifications can be described by HSC with clear visibility of the whole system, and c) the specification development based on specification reuse is possible. The specification development of communication systems can be divided into three processes: (1) specification acquisition, (2) specification description and (3) specification verification. In this paper we will concentrate on specification acquisition part. We will use the language developed by us, HSC, which is very suitable for this purpose. In this work, we noted that hierarchical structure is the characteristic feature of communication software. As the language HSC has inherent hierarchy and modularity, we conjectured it to be suitable for specifying the requirements of communication software. Efficient reuse of components is accomplished by using CBR technique. Furthermore, we propose a specification acquisition method AOBA, and implemented a support environment for it, called AOBA System, using the CBR tool ART-IM. We experimented with the descriptions of communication systems, for example, the descriptions of services in a telephone system using AOBA System. Through these experiments, the effectiveness of AOBA and AOBA System is ensured.