REQUIREMENTS SPECIFICATION FOR PROCESS-CONTROL SYSTEMS

This paper describes an approach to writing requirements specification s for process-control systems, a specification language that supports this approach, and an example application of the approach and the lang uage on an industrial aircraft collision avoidance system (TCAS II). T he example specification demonstrates 1) the practicality of writing a formal requirements specification for a complex, process-control syst em, and 2) the feasibility of building a formal model of a system usin g a specification language that is readable and reviewable by applicat ion experts who are not computer scientists or mathematicians. Some le ssons learned in the process of this work, which are applicable both t o forward and reverse engineering, are also presented.