Integrating real-time structured design and formal techniques

Abstract

As most, if not all, real-time software is also critical, it is not unreasonable to expect developers to use best practice in the production of real-time software. But what is best practice? In terms of development, it would not be unreasonable to expect the use of structured analysis and design methods. In terms of verification of safety/liveness properties, it is not unreasonable to expect the use of a formalism. In general, however, structured methods and formal methods have different ways of modeling a system, so how can we be sure that properties that are proven of a formal model hold for a structured design? The answer is method integration. Method integration is a term commonly used to refer to the combination of a structured analysis or design method with a formal method. In this paper we shall present work on the integration of the structured real-time design method HRT-HOOD, and the real-time formal method Modecharts. We shall discuss the deficiencies of each of the methods, and show that when used together they co-optimize, enabling the user to produce a structured design that is amenable to scheduling analysis, which can also have properties about it verified.

Partly funded by a CASE award from the European Space Agency.