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The Temporal Agent Model (TAM) is a refinement calculus which enables the developer of a real-time system to formally derive a program from a specification of timing and functional requirements. The main objectives of the project is to extend the TAM and the enabling Deadline Monotonic Scheduling theory to address issues of distributed communication, criticality, mode changes, improving utilisation, unbounded algorithms, and dynamic and adaptive systems. Progress:Progress has been made on two fronts: Firstly, significant advances have been made to the enabling Deadline Monotonic Scheduling theory, in particular, and fixed priority scheduling theory in general. The result is that the developed analysis techniques have matured and many are now appropriate for industrial use. The Departments industrial sponsors are now beginning to evaluate the technology for use in their current development process. Furthermore, we are developing a testbed to experiment with some of the more advanced theory. The testbed will also act as a demonstrator of the technology. All of our theoretical objectives have been met, and, by the end of the project, we hope to have achieved our experiment goals. TAM has also matured as a result of case studies by the group and other Universities. The problems of both criticality and distributed computation within the TAM calculus have been investigated. The application of TAM to a safety-critical system case studied developed for the Health and Safety Executive has also been undertaken in order to investigate the utility of TAM for the analysis of criticality.The project has produced many papers, some of which are:N. Audsley, A. Burns, M. Richardson, K. Tindell and A. Wellings, Applying New Scheduling Theory to Static Priority Pre-emptive Scheduling , Software Engineering Journal 8( 5), pp 284-292 ( September 1993) . N.C. Audsley, A. Burns and A.J. Wellings Deadline Monotonic Scheduling Theory and Application , Control Engineering Practice 1(1), pp. 71-78 (1993) . N.C. Audsley, R.I. Davis and A. Burns, Mechanisms for Enhancing the Flexibility and Utility of Hard Real-Time Systems , Proceedings 15th IEEE Real-Time Systems Symposium, San Juan, Puerto Rico, pp. 12-21 (7 - 9 December 1994) .R.I. Davis, K.W. Tindell and A. Burns Scheduling Slack Time in Fixed Priority Preemptive Systems , Proceedings Real-Time Systems Symposium (December 1993).D.J. Scholefield, H.S.M. Zedan and H. Jifeng, A Specification Oriented Semantics for the Refinement of Real-Time Systems , Theoretical Computer Science, Elsevier 131, pp. 219 - 241 (1994) . D.J. Scholefield, Proving Properties of Real-Time Semaphores , Science of Computer Programming, Elsevier (to appear).
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