A METHOD OF FORMAL REQUIREMENT ANALYSIS FOR NPP IC SYSTEMS BASED ON OBJECT-ORIENTED UML MODELING WITH SOFTWARE COST REDUCTION

摘要

This study suggests a formal requirement analysis method for Nuclear Power Plant (NPP) Instrumentation and Control (I&C) systems. The method uses Unified Modeling Language (UML) for modeling systems visually and Software Cost Reduction (SCR) for verifying the systems formally. Since object-oriented methods enable us to analyze problems in terms of the objects in a real system, the UML models are useful for understanding the problems and communicating with people involved in a project. In order to analyze problems more formally, SCR is used and the UML models are converted into the SCR tabular notations. This study tries to acquire the flow-through from UML models to SCR specifications by suggesting additional syntactic extensions for UML notation and a converting procedure. The proposed method has been applied to the Dynamic Safety System (DSS) that are parts of a NPP I&C system. Through these applications, some errors have been detected in the existing system requirements.