Performance and Cost Benefit Analysis of a Hardware-Software System Considering Hardware based Software Interaction Failures and Different Types of Recovery

Abstract

In the present paper a hardware-software system that may have hardware, software and hardware based software interaction failures is taken. It is considered that a hardware and a software failure occurs purely due to respective hardware and software subsystems whereas a hardware based software interaction failure occurs whenever hardware degradation is not detected or repaired by the software method. It is assumed that, in addition to the software methods, recovery of the hardware and the software subsystems upon their failure may respectively be carried out by external hardware and software engineers. The measure of system performance such as mean time to system failure, expected up time of the system, expected down time due to pure hardware failure, expected down time due to pure software failure, expected down time due to hardware based software interactions failure, expected number of software repairs, expected number of hardware repairs, expected number of visits of hardware engineers, expected number of visits of software engineers, expected number of hardware repair by software method and expected number of software repair by re-execution are obtained using Markov process and regenerative point technique. Various conclusions regarding reliability and profit of the system are drawn on the basis of graphical studies. General Terms Stochastic Process