A Safety Mechanism Using Software Patterns

Software patterns have been widely studied in order to reuse of design knowledge in software design phase. However, few patterns have been known in the area of safety. This paper addresses a mechanism for safety and its software pattern in a reactive system. We construct a pattern composed of a mechanism called an event checker including several software patterns to check scenarios, i.e., the order of events and their timing constraints. Next, we show examples of its implementation to railroad models using Java. Moreover, we discuss the safety in the domain of a reactive system by means of this event checker and its software reliability by using this pattern.