A Design Method for Real-Time Object-Oriented Systems Using Communicating Real-Time State Machines

Abstract

Many methodologies for software modeling and design include some form of static and dynamic modeling to describe the structural and behavioral views respectively. Modeling and design of complex real-time software systems requires notations for describing concurrency, asynchronous event handling, communication between independent machines, timing properties. Dynamic modeling of real time systems using object-oriented methodologies requires extensions to the traditional state machine notations in order to convey the real-time system characteristics and constraints. This chapter proposes an object-oriented analysis and design methodology that augments the traditional UML (Unified Modeling Language) dynamic model with real-time extensions based on high-level parallel machines and communication notations from CRSM (Communicating Real-Time State Machines). An example of the proposed methodology is provided using a realistic example of an automated passenger train system.