Software quantitative safety analysis methodology using quality sub-factors in a metro microprocessor signaling system

摘要

The purpose of this paper is to present the application of a software quantitative safety analysis to a metro signaling system. The first step is to determine the software quality sub-factors that can adequately represent the software safety quality factor. For this purpose, this work is based on the ISO/IEC 9126 Standard - Information Technology - Software Product Quality and on the ISO/IEC 14598 Standard - Software Engineering - Product Evaluation. The chosen quality sub-factors that represent the safety quality factor are: accuracy, security, maturity, completeness, fault/error tolerance, understandability, simplicity, consistency, auto-description, time behavior, analyzability, testability, modularity and traceability. The last step corresponds to the application of some of this safety sub-factor metrics over a metro signaling system implemented with microprocessor technology. Finally, some considerations are made in order to associate the desired safety level of the signaling system with the expected values of the software quality sub-factors adopted.