Specification and Quality Assurance of Timing Constraints in Real-time Systems Development

A representation for specifying the timing constraints of real-time systems is presented. Four parts of descriptions in a timing constraint: the path of events, timer, types of constraints and quantities of time, are explained. Under the relations among the paths, the hierarchical and network structures can be conducted. The former can be associated with the structure resulting from applying top-down decomposition in software development. The latter represents the execution dependence of the paths. Based upon these clear and manageable structures, the completeness and consistency of timing constraints specification can be rigorously analysed. Thus, the quality of the specification of timing constraints can be improved during software development. A frame-like software requirements specification language (FSRSL) is extended to specify timing constraints and the related descriptions in the paper.