A Timed Extension of Property Sequence Chart

Property sequence chart (PSC) is a novel scenarios based notation, which is proposed to represent the temporal properties for concurrent system. It represents a first step toward languages that try to balance expressive power and simplicity of use. Thus, PSC is more intuitive and easily understandable than the traditional temporal logic, such as linear-time temporal logic or computation tree logic. However, the current version of PSC just represents the order of eventpsilas occurrence and lacks the ability to express timed properties. In real-time systems, it is well known that some timed requirements are also very important and need to be specified clearly. Thus, in this paper, in order to make PSC have timed expressiveness, we extend PSC into Timed PSC (TPSC) and give the semantics of TPSC in terms of timed Buchi automaton. Then, we measure the expressive power of TPSC by the use of recently proposed real-time specification pattern. Finally, we illustrate the use of TPSC in the context of a Web service application which requires special timed requirements.