A METHODOLOGY AND TOOL FOR MEASUREMENT-BASED DEPENDABILITY EVALUATIONOF DIGITAL-SYSTEMS IN CRITICAL APPLICATIONS

This paper presents an overview of a measurement-based methodology for dependability(2) evaluation of critical digital systems and describes a software tool under development for it. The approach is based on me asurements of operational systems and on dependability models to provi de quantitative reliability and availability assessments with stated c onfidence levels. The methodology is described, and some of the lesson s learned in its early use are discussed. The design of a software too l to implement the methodology is outlined and the current experience in applying the methodology is summarized.