In this research, we consider an application of the Bayesian Inferences in machine replacement problem. The application is concerned with the time to replace two machines producing a specific product; each machine doing a special operation on the product when there are manufacturing defects because of failures. A common practice for this kind of problem is to fit a single distribution to the co...

Abstract In this work, a stress is given on the evaluation of performance measures of a parallel system under priority with necessary conditions on operation and repair times. The units are identical in nature subject to constant failure. There is a single server who visits the system immediately to rectify the faults whenever occurred in the system. The system undergoes for preventive maintena...

The quest for improving the software quality has given rise to various studies which focus on the enhancement of the quality of software through various processes. Code smells, which are indicators of the software quality have not been put to an extensive study for as to determine their role in the prediction of defects in the software. This study aims to investigate the role of code smells in ...

In this paper we quantitatively evaluate the security of intrusion tolerant systems with preventive maintenance subject to DoS (Denial of Service) attacks. More specifically, we develop two semi-Markov cost models and describe the stochastic behavior of two intrusion tolerant systems with different preventive maintenance policies. The optimal preventive maintenance schedules are analytically de...

We study joint preventive maintenance (PM) and production policies for an unreliable production-inventory system in which maintenance/repair times are non-negligible and stochastic. A joint policy decides (a) whether or not to perform PM, and (b) if PM is not performed, then how much to produce. We consider a discrete-time system, formulating the problem as a Markov decision process (MDP) model...

We analyze a system of N components with dependent failure times. The goal is to obtain the optimal block replacement interval (different for each component) over a finite horizon that minimizes the expected total maintenance cost. In addition, we allow each preventive maintenance action to change the future joint failure time distribution. We illustrate our methodology with an example from Sou...

A monitored system consists of a core system and its monitor. A core system follows a general life time distribution, but its state, good or not good, cannot be observed directly. In order to infer the state of the core system, we use the information from the monitor whose states are stochasticalIy related to the states of the core system. Using its information, we make the maintenance policy f...