In this paper, we propose a software reliability model that considers not only error generation but also fault removal efficiency combined with testing coverage information based on a nonhomogeneous Poisson process (NHPP). During the past four decades, many software reliability growth models (SRGMs) based on NHPP have been proposed to estimate the software reliability measures, most of which ha...

ConclusionsBased on the nature of the upperand lower-bound block diagram models of Multistage Interconnection Networks (MINs), we generalize and consider a series system consisting of independent subsystems. In order to model the reliability of such a system with on-line repair and imperfect coverage, the usual approach is to construct and solve a large, overall Markov model. Instead, we propos...

In this paper, an analytical approach for the availability evaluation of cellular manufacturing systems is presented, where a manufacturing system is considered operational as long as its production capacity requirements are satisfied. The advantage of the approach is that constructing a system level Markov chain (a complex task) is not required. A manufacturing system is decomposed into two su...

The present study deals with a robot safety system composed of standby robot units and inbuilt safety unit. When the main operative unit fails, it is replaced by the standby robot unit available in the system. The concept of reboot delay is also incorporated in this study according to which the robot unit is rebooted if it is not successfully recovered. The recovery and reboot times of failed u...

In the present investigation, we deal with the reliability characteristics of a repairable system consisting of two independent operating units, by incorporating the coverage factor. The probability of the successful detection, location and recovery from a failure is known as the coverage probability. The reboot delay and common cause shock failure are also considered. The times to failure of t...

In this paper we develop a search procedure for redundancy optimization of reliability models. We consider those systems where the reliability cannot be evaluated exactly but must be estimated through Monte Carlo simulation. At each iteration, two neighboring configurations are compared and the one that appears to be better is passed on to the next iteration. The search procedure uses an incre...

Reliability importance analysis is usually used to detect design weakness, to identify which components contribute the most to the failure of a system, and thus to help find the most cost-effective way for upgrading the system. In this paper, we consider the reliability importance analysis of components in a generalized phased-mission system using the Birnbaum’s measure. Our method is based on ...

We consider the dependability analysis of hierarchical fault tolerant computer based systems in this paper. The hierarchical nature of the system aids in fault coverage: if an undetected error escapes from one level of the system, it may be covered or tolerated at a higher level. A fault that remains uncovered through all levels of the hierarchy, and thus appears at the output, causes immediate...