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Abstract In this paper, an efficient analytical modeling method is proposed for reliability analysis of k-out-of-n phased-mission systems (PMSs). A PMS is a system involving multiple, consecutive and non-overlapping phases of tasks during... more
Abstract In this paper, an efficient analytical modeling method is proposed for reliability analysis of k-out-of-n phased-mission systems (PMSs). A PMS is a system involving multiple, consecutive and non-overlapping phases of tasks during its mission, which abounds in complex technological systems such as aerospace systems, nuclear power plants, and high-performance computing systems. Due to dynamics in the system configuration and component behavior as well as statistical dependences across phases, exact reliability evaluation of a PMS is a time-consuming and complicated task. This paper proposes a new efficient multi-valued decision diagram (MDD) based method for the reliability analysis of a special class of non-repairable PMSs called k-out-of-n PMS where the same number of components n is involved in all the phases but the required number of working components k may vary from phase to phase. Particularly, a new MDD generation method is proposed for a fast construction of the PMS MDD model. The system components are not necessarily identical; they can be heterogeneous in their failure time distributions. Examples are provided to demonstrate the application and advantages of the proposed methodology.
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Abstract Almost every engineering and manufacturing system consists of several subsystems, which are in general nonidentical and are subjected to stochastic failures and repairs. The system success logic can be represented using a... more
Abstract Almost every engineering and manufacturing system consists of several subsystems, which are in general nonidentical and are subjected to stochastic failures and repairs. The system success logic can be represented using a combinatorial reliability ...
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Many practical systems are phased-mission systems (PMSs), where the mission consists of multiple, consecutive, and non-overlapping phases of operation. An accurate reliability analysis of a PMS must consider statistical dependence of... more
Many practical systems are phased-mission systems (PMSs), where the mission consists of multiple, consecutive, and non-overlapping phases of operation. An accurate reliability analysis of a PMS must consider statistical dependence of component states across phases, as well as dynamics in system configurations, success criteria, and component behavior. This paper proposes a new method based on multiple-valued decision diagrams (MDDs) for the reliability analysis of a non-repairable binary-state PMS. Due to its multi-valued logic nature, the MDD model has recently been applied to the reliability analysis of multistate systems. In this work, we present a novel way to adapt MDDs for the reliability analysis of systems with multiple phases. Examples show how the MDD models are generated and evaluated to obtain the mission reliability measures. Performance of the MDD-based method is compared with an existing binary decision diagram (BDD)-based method for PMS analysis. Empirical results show that the MDD-based method can offer lower computational complexity as well as a simpler model construction and improved evaluation algorithms over those used in the BDD-based method.
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Abstract The authors comment on the paper by J. Xue and K. Yang (see ibid., vol. 44, p. 683-8, 1995) Some typographical errors and their correct versions are given. Two of the errors were pointed out by the original authors in their... more
Abstract The authors comment on the paper by J. Xue and K. Yang (see ibid., vol. 44, p. 683-8, 1995) Some typographical errors and their correct versions are given. Two of the errors were pointed out by the original authors in their correspondence with the responsible ...
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Abstract This paper maximizes the reliability of systems subjected to imperfect fault-coverage. The results include the effect of common-cause failures andmaximum allowable spare limit'. The generalized results are... more
Abstract This paper maximizes the reliability of systems subjected to imperfect fault-coverage. The results include the effect of common-cause failures andmaximum allowable spare limit'. The generalized results are presented and then the policies for some specific ...
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... First published February 10, 2009; current version pub-lished March 04, 2009. Associate Editor: G. Levitin. SV Amari and G. Dill are with Relex Software Corporation, Greensburg, PA 15601 USA (e-mail: suprasad.amari@relex.com;... more
... First published February 10, 2009; current version pub-lished March 04, 2009. Associate Editor: G. Levitin. SV Amari and G. Dill are with Relex Software Corporation, Greensburg, PA 15601 USA (e-mail: suprasad.amari@relex.com; glenn.dill@relex.com). ...
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This index covers all technical items-papers, correspondence, reviews, etc.-that appeared in this periodical during the year, and items from previous years that were commented upon or corrected in this year. Departments and other items... more
This index covers all technical items-papers, correspondence, reviews, etc.-that appeared in this periodical during the year, and items from previous years that were commented upon or corrected in this year. Departments and other items may also be covered if they have been judged to have archival value. The Author Index contains the primary entry for each item, listed under the first author's name. The primary entry includes the co-authors' names, the title of the paper or other item, and its location, specified by the ...
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This index covers all technical items-papers, correspondence, reviews, etc.-that appeared in this periodical during the year, and items from previous years that were commented upon or corrected in this year. Departments and other items... more
This index covers all technical items-papers, correspondence, reviews, etc.-that appeared in this periodical during the year, and items from previous years that were commented upon or corrected in this year. Departments and other items may also be covered if they have been judged to have archival value. The Author Index contains the primary entry for each item, listed under the first author's name. The primary entry includes the coauthors' names, the title of the paper or other item, and its location, specified by the ...
... Suprasad V. Amari, Ph.D., Relex Software Corporation, Greensburg Jennifer B. Akers, Relex Software Corporation, Greensburg ... evaluation, but also include various other measures such as failure (hazard) rate, failure (occurrence)... more
... Suprasad V. Amari, Ph.D., Relex Software Corporation, Greensburg Jennifer B. Akers, Relex Software Corporation, Greensburg ... evaluation, but also include various other measures such as failure (hazard) rate, failure (occurrence) frequency, MTTFF (Mean Time To First Failure ...
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In this chapter, a state-of-the-art review of fault tree analysis is presented. Different forms of fault trees, including static, dynamic, and non-coherent fault trees, their applications and analyses will be discussed. Some advanced... more
In this chapter, a state-of-the-art review of fault tree analysis is presented. Different forms of fault trees, including static, dynamic, and non-coherent fault trees, their applications and analyses will be discussed. Some advanced topics such as importance analysis, dependent failures, disjoint events, and multistate systems will also be presented.
Many practical systems are phased-mission systems (PMS) where the mission consists of multiple, consecutive, and non-overlapping phases. An accurate reliability analysis of a PMS must consider the statistical dependencies of component... more
Many practical systems are phased-mission systems (PMS) where the mission consists of multiple, consecutive, and non-overlapping phases. An accurate reliability analysis of a PMS must consider the statistical dependencies of component states across phases as well as dynamics in system configuration, success criteria and component behavior. In this paper, we propose an efficient method for exact reliability evaluation of k-out-of-n systems with identical components subject to phased-mission requirements where the k values and failure time distributions can change with the phases. We also consider the time-varying and phase-dependent failure rates and associated cumulative damage effects. The proposed method is based on conditional probabilities and an efficient recursive formula to compute these probabilities. The main advantage of this method is that both its computational time and memory requirements are linear in terms of the system size.
Many fielded systems use cold standby redundancy as an effective system design strategy. However, methods for analyzing the reliability of k-out-of-n cold standby systems, particularly with components having age-dependent hazard rates,... more
Many fielded systems use cold standby redundancy as an effective system design strategy. However, methods for analyzing the reliability of k-out-of-n cold standby systems, particularly with components having age-dependent hazard rates, are limited. In this paper, using the concepts of counting processes, we propose an efficient method to evaluate the reliability of k-out-of-n cold standby systems. This proposed method considers Erlang distributions for component lives and the effects of switch failures on system reliability. The main advantage of this counting process-based method is that it reduces a complex problem involving multiple integrals into an equivalent simple problem involving one-dimensional convolution integrals. We consider the Erlang distribution for three reasons: (1) it can be used to model either constant or increasing hazard rates, (2) it can be used to approximate several component failure time distributions, and (3) it has well established closed-form expressio...
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s will be due Saturday, 15 April 2017. Accelerated Life Testing Availability Big Data and IoT Applications in R&M Business Process Improvement Design Optimization Using R&M Techniques Discrete Event Modeling & Simulation Economic Models... more
s will be due Saturday, 15 April 2017. Accelerated Life Testing Availability Big Data and IoT Applications in R&M Business Process Improvement Design Optimization Using R&M Techniques Discrete Event Modeling & Simulation Economic Models for R&M Equipment Diagnostics and Prognostics FMEA Fault Tolerance and Safety Critical Systems Fault Tree Analysis Human Reliability Knowledge Based Training Life Data Analysis Maintenance Models and Methodologies Physical Reliability Models Prognostics and Health Management Quality Appl. in Electronics Design & Mfg. R&M Applications in Aerospace R&M Applications in Health Care R&M Applications in Infrastructure Management R&M Applications in Manufacturing R&M Applications in Service R&M Applications in Supportability R&M and Quality Appl. in Communications Design & Mfg. R&M Management Reliability Modeling Reliability Growth Analysis Repairable Systems Risk Analysis and Management Security and Dependability Analysis Software Reliability and Testing S...
Dynamic fiber bundle models are useful tools in explaining dynamic failure behavior in heterogeneous materials. Such models shed light on diverse phenomena such as fatigue in structural materials and earthquakes in geophysical settings.... more
Dynamic fiber bundle models are useful tools in explaining dynamic failure behavior in heterogeneous materials. Such models shed light on diverse phenomena such as fatigue in structural materials and earthquakes in geophysical settings. The load-sharing concepts and models used in the fiber bundle models have a direct application in textile engineering (fibers), material science and testing (fatigue and crack growth), and structural engineering (welded joints on large support structures) disciplines. In addition, these models are also useful in biological and medical sciences. While much attention has been devoted to static or fast-fracture strength, where material elements are assumed time independent, dynamic models describing creep-rupture and fatigue lifetime are perhaps even more important. Building good theoretical models has proven straightforward, but analyzing them has required delving into statistical details of the interaction of various flaw features and failure configur...
In this paper we consider the problem of reliability modeling and analysis of hierarchical computer-based systems (HS) with modular imperfect coverage (MIPC) and common-cause failures (CCF). The MIPC and CCF can cause vertical dependence... more
In this paper we consider the problem of reliability modeling and analysis of hierarchical computer-based systems (HS) with modular imperfect coverage (MIPC) and common-cause failures (CCF). The MIPC and CCF can cause vertical dependence that runs through different levels of the system as well as horizontal dependence that runs across components or modules on the same system level. The consideration of these dependencies poses unique challenges to existing HS reliability analysis methods. We propose an efficient decomposition and aggregation approach named EDA-HS to the reliability evaluation of complex hierarchical systems with both MIPC and CCF as one way to meet the above challenges in an efficient and elegant manner. Our approach is to decouple the effects of both MIPC and CCF from the combinatorics of the solution. The approach is represented in a dynamic fault tree by a proposed probabilistic functional dependency gate and a proposed CCF gate modeled after the existing FDEP gate. We present the basics and advantages of the EDA-HS approach by working through an analysis of an example HS subject to MIPC and CCF.
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The use of warranty claims data to determine the failure characteristics of a product is well documented. Typically, existing techniques assume that the product ages at the times of failure are known or can be derived based on product... more
The use of warranty claims data to determine the failure characteristics of a product is well documented. Typically, existing techniques assume that the product ages at the times of failure are known or can be derived based on product manufacturing data for each month of production and the corresponding monthly failure counts derived from the warranty claims. However, our experience shows that, in many cases, it may not be possible to know the failure ages of components. The information available from each month might be limited to the volume of shipments and total claims or product returns. In these cases, the data hides the component age at the time of failure. In this paper, we show that when the failure history information is incomplete, the failure distribution of the product can be determined using Bayesian analysis techniques applicable for handling incomplete data. The popular Expectation-Maximization (EM) algorithm is applied to find the Maximum Likelihood Estimates (MLE) o...
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... The collection of pairs gjh, pjh, h= 0, 1,...,kj, completely determines the performance distribution of element j. When the MSS consists of n independent elements, its performance rate is unambiguously determined by the performance... more
... The collection of pairs gjh, pjh, h= 0, 1,...,kj, completely determines the performance distribution of element j. When the MSS consists of n independent elements, its performance rate is unambiguously determined by the performance rates of these elements. ...
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ABSTRACT With the development of technology, sensor networks, and non-conventional power generators, weapon equipments become more and more complex, and their missions become more and more diversified. Further, many real world systems... more
ABSTRACT With the development of technology, sensor networks, and non-conventional power generators, weapon equipments become more and more complex, and their missions become more and more diversified. Further, many real world systems operate in phased-missions where the system requirements and success criteria vary over consecutive time periods, known as phases. For mission success, all phases must be completed without failure. In order to ensure accomplishing missions successfully, many subsystems adopt redundancy techniques to improve the mission reliability. Particularly, redundancy is an effective method to improve the reliability of mission critical systems. Hence, there is a great need for accurate and efficient reliability evaluation of phased mission systems with phase dependent redundancy configurations and requirements. This paper presents a new method for reliability analysis of phased-mission systems with warm standby subsystems. In the analysis, multiple sub-systems were considered where each sub-system uses warm standby redundancy. The operational and standby failure rates of a component can vary with the phases. Similarly, the configuration of each subsystem can vary with the phases. The proposed algorithm is developed based on: (1) a modularization technique, (2) an easily computable closed-form expressions for conditional reliability of warm standby sub-systems with phased dependent success criteria, and (3) a recursive formula for accounting the dependencies of sub-systems across the phases. As cold and hot standby configurations are special cases of warm standby configuration, the proposed method is also applicable for analyzing the phased mission systems with cold and hot standby redundancies. The reliability evaluation algorithm is illustrated using an example of fault tolerant computing system.
ABSTRACT This paper presents a new model for load-sharing systems using k-out-of-n structure. It is assumed that the failure distribution of each component at a baseline load follows a general failure time distribution. Hence, the model... more
ABSTRACT This paper presents a new model for load-sharing systems using k-out-of-n structure. It is assumed that the failure distribution of each component at a baseline load follows a general failure time distribution. Hence, the model can be used for analyzing the systems where components' failure times follow Weibull, Gamma, Extreeme Value, and Lognormal distributions. In a load-sharing system, the system components experience different loads at different time intervals due to the load-sharing policy. Therefore, to analyze the reliability of load-sharing systems, the failure rate of each component must be expressed in terms of the current load and the current age of the component. In this paper, the load-dependent time-varying failure rate of a component is expressed using Cox's proportional hazards model (PHM). According to the PHM the effects of the load is mulitplicative in nature. In other words, the hazard (failure) rate of a component is the product of both a baseline hazard rate, which can be a function of time t, and a multiplicative factor which is function of the current load on the component. The load-sharing model also considers the switchover failures at the time of load redistribution. We first show that the model can be described using a non-homogeneous Markov chain. Therefore, for the non-identical component case, the system reliability can be evaluated using well established methods for non-homogenerous Markov chains. In addition, when all components are identical, the paper provides a closed-form expression for the system reliability even when the underlying baseline failure time distribution is non-exponential. The method is demonstrated using a numerical example with components following Weibull baseline failure time distribution. The numerical results from non-homogeneous Markov chains, closed-form expressions, and Monte Carlo simulation are compared.
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Remember Me Forgot your password? Forgot your username? Sunday, January 29, 2012. HOME; ABOUT IJPE: SCOPE OF THE JOURNAL; ABOUT THE JOURNAL; CONTRIBUTION GUIDELINES. JOURNAL COVERAGE: CURRENT ...
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ABSTRACT
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Abstract The traditional static fault trees with AND, OR and voting gates cannot capture the dynamic behavior of system failure mechanisms such as sequence-dependent events, spares and dynamic redundancy management and priorities of... more
Abstract The traditional static fault trees with AND, OR and voting gates cannot capture the dynamic behavior of system failure mechanisms such as sequence-dependent events, spares and dynamic redundancy management and priorities of failure events. Therefore, ...
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Page 1. Reliability Analysis of Tampered Failure Rate Load-Sharing k-out-of-n:G Systems Suprasad V. Amari Relex Software Corporation 540 Pellis Road Greensburg, PA 15601 USA Krishna B. Misra RAMS Consultants 71 Vrindaban Vihar Ajmer Road,... more
Page 1. Reliability Analysis of Tampered Failure Rate Load-Sharing k-out-of-n:G Systems Suprasad V. Amari Relex Software Corporation 540 Pellis Road Greensburg, PA 15601 USA Krishna B. Misra RAMS Consultants 71 Vrindaban Vihar Ajmer Road, Jaipur-302 019 India ...
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ABSTRACT