Commonly reliability data consist of lifetimes (or censoring information) on all components and systems under examination. However, masked system lifetime data represents an important class of problems where the information available for statistical analysis is more limited: one only has failure times for the system as a whole, but no data on the component lifetimes directly, or even which comp...

ARTICLE INFO ABSTRACT Keywords: Dependability Consecutive-k-out-of-n: F repairable system Rare-event simulation RESTART The reliability of consecutive-fc-out-of-n: F repairable systems and (fc-l)-step Markov dependence is studied. The model analyzed in this paper is more general than those of previous studies given that repair time and component lifetimes are random variables that follow a gene...

In this paper the dynamic modeling of repairable and standby components of complex systems is analyzed using Petri Nets and ladder logic diagrams. The use of Petri Nets as modelling of a complex system avoids two basic disadvantages of Markov chain analysis. First, the Petri Net model does not grow in size as increasing the number of components and second, Markov chain has been limited to the e...

Research in traditional reliability theory is based mainly on probist reliability, which uses a binary state assumption and classical reliability distributions. In the present paper the binary state assumption has been replaced by a fuzzy state assumption, thereby leading to profust reliability estimates of a repairable system, which is modeled as a four unit gracefully degradable system using ...

We consider the problem of modelling the reliability of a network of subsystems where each subsystem has redundancy and is repairable. The motivation for this work is large-scale telecommunications networks. The time to failure of the subsystem hardware is modeled by an appropriate Markov process and is hence a phase-type distribution. The network structure defines a failure rule in terms of th...

In this paper we study asymptotic behaviour of marked point processes describing failure processes of repairable systems in which repair decisions depend on the past. Under natural conditions on system parameters such processes admit unique time stationary distributions and are ergodic. Convergence of moments and mean number of failures as well as central limit theorems will be established. The...

this paper discusses the performance evaluation and availability analysis of ammonia synthesis unit of a fertilizer plant. the fertilizer plant is a complex and repairable engineering system comprises of various units viz. shell gasification and carbon recovery, desulphurization, co-shift conversion, decarbonation, nitrogen wash and ammonia synthesis etc. one of the most important functionaries...

The need for the combined performance and reliability analysis of fault tolerant systems is increasing. The common approach to formulating and solving such problems is to use (semi-)Markov reward models. However, the large size of size of state spaces is a problem that plagues Markovian models. Combinatorial models have been used for modeling reliability and availability of complex systems with...

* Corresponding author. Tel.: +44 1483 686593; Fax: +44 1483 686581. Email: [email protected] Abstract This paper investigates replacement scheduling for non-repairable safety-related systems (SRS) with multiple components and states. The aim is to determine the cost-minimizing time for replacing SRS while meeting the required safety. Traditionally, such scheduling decisions are made without ...