Conceptual Modeling for Safety Critical Computer Systems

The usefulness and requirement of conceptual model for real-time safety-critical computer systems (SCCS), in the context of software development, is pointed out in literature. The conceptual model is a model of the application domain and the system embedded in it, as perceived by the users and the development team. The conceptual model provides a complete "logical view" of the system and its application domain. This paper proposes a conceptual modeling of real-time systems in general and SCCS architecture in particular using the abstraction of hierarchy of virtual machines by specifically including system safety issues and logical design approach. Virtual machine is an abstract interface definition, representing the visible features at that particular level of system description. Each virtual machine presents a logical interface to the level above it, in terms of a set of user-visible system functions. Logical domain view and logical system view are mapped for obtaining high-level logical architecture With the help of the level crossing controller example, the conceptual model approach is illustrated.