It is generally accepted that requirement models for real-time systems may benefit from the use of formal specifications. In order to be able to evaluate notations for use in the development of real-time software systems, we are performing a comparitive review of some selected specification notations. The study emphasizes the use of the notations in the domain of real-time (control) applications. Our review will be based on a simple railroad controller model. This case contains data modeling aspects, functional aspects as well as temporal aspects. A (toy) railroad with computer interface, is available in our laboratory, used for lab assignments. An Ada encoded controller, loosely based on the specification in this report, is running on a PC for demonstrations. Typical elements to consider are usability with regard to the specification in relation to the requirements, and second, usability with respect to further programme development. In this report we discuss the problem as well as a ...

It is generally accepted that development of requirement models for real-time systems benefits from formal specifications. In order to be able to evaluate notations for use in the development of real-time software systems, we are performing a comparative review of some selected specification notations. The study emphasizes the use of the notations in the domain of real-time (control) applications. Our review will be based on a specification from a simple railroad controller model. This case contains data modelling aspects, functional aspects as well as temporal aspects. A (toy) railroad with a computer interface, is available in our laboratory, used for lab assignments. Typical elements to consider are usability with regard to the specification in relation to the requirements, and second, usability with respect to further program development. This report discusses the problem as well as a model specification, written in Astral. It also discusses verification issues using the proof assi...

The implementation phase of the software development process requires techniques for the transformation of a design specification into software. Although timing analysis of real-time software has got much attention the implementation of design specifications is hardly addressed. In this paper we report on our work on defining mappings for design specifications of real-time distributed control systems onto implementation models. The specification notation we use is ASTRAL [1], a formal real-time specification language. Our target language is Ada95 [2]. In this paper the mapping of ASTRAL specifications on the Ada tasking model is discussed. Main emphasis is put upon the use of timing analysis to verify the correctness of the implementation with respect to the specification. 1 Introduction Current practice in the development of software for embedded real-time control applications has some drawbacks when considered from a software engineering point of view [3]. Current methodologies hard...

It is generally accepted that requirement models for real-time systems may benefit from the use of formal specifications. In order to be able to evaluate notations for use in the development of real-time software systems, we are performing a comparitive review of some selected specification notations. The study emphasizes the use of the notations in the domain of real-time (control) applications. Our review will be based on a simple railroad controller model. This case contains data modeling aspects, functional aspects as well as temporal aspects. A (toy) railroad with computer interface, is available in our laboratory, used for lab assignments. An Ada encoded controller, loosely based on the specification in this report, is running on a PC for demonstrations. Typical elements to consider are usability with regard to the specification in relation to the requirements, and second, usability with respect to further programme development. In this report we discuss the use of the PAISLey no...