One of possible approaches to estimate availability of distributed hardware and software systems

Methods of evaluation of condition and operability of complex distributed systems are considered in this paper. Author propose a new conceptual model of multi-stage complex performance evaluation based on multi-criteria function including various performance, reliability, stability characteristics indicating their contribution to general system performance. The approach used makes it possible to obtain an integrated assessment of system availability taking into account hardware and software reliability analysis as well as influence of various factors (hardware, software, operator's errors) on overall system condition. The Complex Population Notification and Warning System was considered as a subject of the research and was used to test the model developed.