Attribute model of software dependability assessment and its practical application

Abstract

Abstract. The article is devoted to the issue of using the attribute model of dependability (AMD) to quantify the level of software dependability. Building an AMD of software is one of the most important stages of reliability assessment that allows for determining the need to use certain characteristics (attributes) of a software product. The completeness and adequacy of the used system of characteristics determine the reliability of the obtained reliability assessment. Two examples of a medical software are considered in the paper. From the laboratory information system (1-LIS), which automates the work of a medical laboratory, to the critical medical system (2-MS) for monitoring human life after resuscitation, which includes a comprehensive solution that allows for optimizing the patient’s treatment process. A comparison of the generalized characteristics of assurance was made. The attribute model of dependable software AMD was created and extended with special attributes and metrics in accordance with the requirements of DSTU ISO/IEC 25051:2016 Engineering of systems and software, requirements for the quality of systems and software and its evaluation (SQuaRE), and quality requirements for a ready-to-use software product (RUSP) and instructions for its testing (ISO/IEC 25051:2014, IDT). The article uses the mathematical representation of the AMD, which is intended to calculate the level of software dependability. The functional GАМD is used, the components of which are the expert normalized values of quantitative assessments of attributes and metrics with the corresponding weighting factors and influence factors. In order to evaluate the performance of the attribute model of software reliability, two variants of the model were analyzed, with and without weighting the metrics evaluation criteria. In addition, the attribute model of software reliability was tested on two types of software ― with low reliability requirements (the first software package) and high requirements (the second critical software package).