Extending the SCR method for real-time systems

We propose timed SCR specifications, which are a generalization of SCR spec ifications, intended to specify quantitative timing properties of real-time systems. We extend the tabular notation of the SCR method to deal with spo radic and periodic timing constraints. We present a formal semantics for ti med SCR specifications by translating them into timed transition systems. A shutdown system in Korean nuclear power plants is used as a case study to illustrate timed SCR specifications.