Similarity for reuse of specifications in communication software development

The reuse of existing software is one of the most effective ways for software development. We have focused on the specification process with FDTs (Formal Description Techniques), and have proposed a new concept of similarity based on LTSs (Labelled Transition Systems) as a criterion to reuse specifications. However, it's definition has some problems, such that (a) it can't be applied to an LTS with some loops, and (b) the definition of similarity between actions is not clearly expressed. In this paper, we remove these problems in order for our approach to be widely applicable. For the first problem, we extend the definition of similarity to be able to apply to an LTSs with some loops. For the second one, we consider that the similarity of actions is defined based on not only the name of actions, but also the attribute of actions and the way of occurrence of actions as the temporal ordering.