Automatic modification of a protocol specification based on changes of a service specification

The problem of modifying an existing protocol specification of a communicating system in Labelled Transition System (LTS) based on changes of it's service specification in LTS is discussed. Two types of changes of a service specification are treated: addition of a behaviour expression to the service specification and deletion of some parts of the behaviour expression from the service specification. For each change, a modification method is proposed and a property of the method is shown. From the point of view of verification and validation of a specification, it is desirable to separate a changed part of the specification from the existing specification. Thus, especially for the former type of changes that is addition of a behaviour expression to the service specification, the method to express changes of the service specification by using a concurrent LTS is proposed. The method proposed in this paper is efficient and desirable when the size of the changed part of the service specification is small in terms of behaviour expressions.