A formal method for event-triggered sequential systems

Abstract

We present a software development method for event-triggered sequential systems, where we extend a widely used formal Z technique to specify also different kinds of activation of operations and the availability of input and output values. Beside the system operations we also specify the operations of the environment. A data flow diagram serves to specify where an operation belongs to. We define a formal semantics for such specifications by a translation to fair transition systems. Requirements can then be expressed in linear temporal logic. We apply our formal method to a lift already specified with the Z technique and detect a specification fault indicating a drawback of the Z technique for which we suggest a solution.