Graphical development of consistent system specifications

Abstract

While formal methods have promised essential benefits for the software development process, industrial development reality nevertheless relies mainly on informal and especially graphical description techniques. This article argues that formal techniques are indeed useful for practical application, but they should be put to indirect use. To demonstrate this approach, two pragmatic graphical description techniques, taken from the field of telecommunication, are analyzed regarding their information content and their application in the process of specification development; as a result these techniques are formally defined. Based on the formal definition, “safe” development steps and their graphical counterparts are introduced. This yields a graphical development method which relies on precise formal foundations.