Engineering oriented dependability evaluation: MEADEP and its applications

MEADEP is a user-friendly dependability evaluation tool for measurement-based analysis of completing systems. Features of MEADEP include: a data processor for converting data in various formats to the MEADEP format, a statistical analysis module for graphical data presentation and parameter estimation, a graphical modeling interface for building reliability block diagrams and Markov chains, a library of dependability models for constructing customer models, and a model solution module for availability/reliability calculations with graphical parametric analysis. Use of the tool on failure data from measurements can provide objective evaluations of dependability for critical systems, while greatly reducing requirements for specialized skills in data processing, analysis, and modeling from the user. MEADEP has been applied to evaluate availability for two air traffic control systems based on operational failure data and results produced by MEADEP have provided valuable feedback to the project management of these critical systems. MEADEP has also been used to analyze a nuclear power plant safety model, based on the Eagle 21 architecture and its early field failure data, and results of sensitivity analysis on the model are discussed.