修理设备可更换且修理工多重延误休假的单部件可修系统

假定部件的寿命、修理时间和修理工的休假时间均服从一般连续型分布.修理工的延误休假时间服从指数分布,并且修理设备的寿命服从爱尔朗分布,其更换时间服从一般连续型分布的情况下,研究了修理设备可更换且修理工可多重延误休假的单部件可修系统.通过使用补充变量法、广义马尔可夫过程方法和拉普拉斯变换工具,讨论了系统的瞬时可用度、稳态可用度以及(0,t]时间内系统的平均故障次数和稳态故障频度,得到了系统和修理设备主要可靠性指标的拉普拉斯变换表达式.     

专职修理工多重休假且修理设备可更换的k/n(G)表决系统研究

讨论专职修理工多重休假,修理设备可发生失效且可更换的k/n(G)表决可修系统.当系统中没有故障部件时,专职修理工开始一次休假,在此期间,若有工作部件发生故障,则立即指派普通修理工修理故障部件,一直持续到系统中无故障部件或专职修理工休假回来.利用马尔可夫过程理论和矩阵解法,给出了系统瞬态和稳态下的可用度和故障频度、可靠度、系统首次故障前的平均时间、修理设备处于更换状态的概率等指标的表达式.在此基础上,基于不同的初始条件研究了相关指标随时间的变化情况.最后,特殊情形的讨论验证了所得结果的正确性.     

修理设备可更换且有修理延迟的N部件串联系统分析

假定部件的寿命服从指数分布,修理延迟时间和修理时间均服从任意分布,并且修理设备的寿命服从指数分布,其更换时间服从任意分布的情况下,利用马尔可夫更新过程理论和拉普拉斯变换工具,研究了修理有延迟且修理设备可更换的n部件串联可修系统,求得了系统的可用度和(0,t]时间内的平均故障次数.进一步,在定义修理设备“广义忙期”下,利用全概率分解,提出了一种新的分析技术,讨论了修理设备的可靠性指标,得到修理设备的一些重要可靠性结果.     

修理设备可更换和修理延迟的两类故障状态并联可修系统

考虑两同型部件组成的并联可修系统,每个部件有两类故障状态,部件故障后修理有延迟,且修理设备在修理故障部件的过程中也可能发生故障.假定部件的寿命和修理设备的寿命服从指数分布,部件发生故障后的修理延迟时间、修理时间和修理设备故障后的更换时间均服从一般分布,利用马尔可夫更新过程理论和拉普拉斯变换工具,求得了系统有关的可靠性指标.     

专职修理工多重休假且修理设备可更换的k/n(G)表决系统研究

讨论专职修理工多重休假,修理设备可发生失效且可更换的k/n（G）表决可修系统.当系统中没有故障部件时,专职修理工开始一次休假,在此期间,若有工作部件发生故障,则立即指派普通修理工修理故障部件,一直持续到系统中无故障部件或专职修理工休假回来.利用马尔可夫过程理论和矩阵解法,给出了系统瞬态和稳态下的可用度和故障频度、可靠度、系统首次故障前的平均时间、修理设备处于更换状态的概率等指标的表达式.在此基础上,基于不同的初始条件研究了相关指标随时间的变化情况.最后,特殊情形的讨论验证了所得结果的正确性.     

修复率可变化的表决系统可靠性分析

研究了具有维修速率可变化的k/n(G)表决可修系统,其中部件的工作时间和修理时间均服从负指数分布.开始时,当系统中的故障部件数小于某一阈值L时,修理工以较低的维修率修理故障的部件.如果修理工修理工作进展不顺利,故障部件数增加到阈值L时,将立即以较快的速度修理故障部件,此状态一直持续到系统中没有故障部件为止.使用马尔可夫过程理论和分析方法,得到了系统可用度、故障频度、系统首次故障前的平均时间等指标的表达式.进一步,讨论了不同条件下系统相关指标随系统参数变化的情况,并通过对特殊情形的讨论数值验证了所得结果的正确性.     

部件有两类故障状态且修理设备可更换的并联可修系统分析

本文考虑由两个同型部件组成的并联可修系统,每个部件有两类故障状态,部件故障后立即修理,且修理设备在修理故障部件的过程中也可能发生故障.假定部件的寿命和修理设备的寿命均服从指数分布,部件发生故障后的修理时间和修理设备故障后的更换时间均服从一般分布,利用马尔可夫更新过程理论,求得系统的有关可靠性指标和修理设备的闲期长度和"广义忙期"长度等一系列结果.     

修理设备可更换且修理有延迟的两不同型部件并联可修系统

假定部件的寿命服从指数分布,其修理延迟时间和修理时间均服从一般分布,并且修理设备的寿命服从指数分布,其更换时间服从一般分布,利用马尔可夫更新过程理论和一种新的分解方法,研究了修理设备可更换且修理有延迟的两不同型部件并联可修系统,求得了系统和修理设备有关可靠性指标的一系列结果.     

修理设备可修修理延迟的N个部件串联系统的随机性状及可靠性分析北大核心CSCD

考虑N(N≥2)个同型部件串联可修系统的随机性状及修理设备的可靠性.假设修理设备在修理失效部件的过程中可能失效,失效后的修理设备需要立即修理,部件失效后需要一段随机的延迟修理时间.进一步假定系统失效后好的部件可能劣化.利用马尔科夫更新过程工具和Takács的方法,研究系统的随机性状并利用随机性状研究结果得到该系统修理设备在时刻t的失效概率以及修理设备在(O,t)内的故障次数和故障频度以及一些有意义的推论.     

修理设备可更换的N-策略延迟不中断单重休假M/G/1可修排队系统分析

该文考虑具有N-策略和延迟不中断单重休假的M/G/1可修排队系统,其中修理设备在修理故障服务台期间可发生故障且可更换.该文运用更新过程理论,全概率分解技术和拉普拉斯变换工具,讨论了服务台和修理设备的可靠性指标,比如服务台和修理设备的瞬态不可用度,稳态故障频度以及在时间(0,t]内的平均故障次数等,并且对服务台的稳态不可用度和稳态故障频度进行了参数敏感性分析.     

具有不同失效率和修理率的n中连续取k的可修系统

研究了具有不同失效率和修理率的,2中连续取k的可修系统．在假设失效部件的修理规则为后到先修,且修复如新的条件下,得到了具有不同失效率和修理率的n中连续取k的可修系统各状态的概率,并进一步获得了这类可修系统的一些重要的可靠性指标或者其Laplace变换．     

A study of repairable parts inventory system operating under performance-based contract

Performance-Based Logistics (PBL) is becoming a dominant logistics support strategy, especially in the defense industry. PBL contracts are designed to serve the customer’s key performance measures, while the traditional contracts for after-sales services, such as Fixed-price (FP) and Cost-plus (C+), only provide insurance or incentive. In this research, we develop an inventory model for a repairable parts system operating under a PBL contract. We model the closed-loop inventory system as an M/M/m queue in which component failures are Poisson distributed and the repair times at the service facility are exponential. Our model provides the supplier and the customer increased flexibility in achieving target availability. Analysis of key parameters suggests that to improve the availability of the system with repairable spare parts, the supplier should work to improve the components reliability and efficiency of repair facility, rather than the base stock level, which has minimal impact on system availability.     

Optimal repair allocation in a series system expected discounted operation time criterion

Consider a series system with n repairable components maintained by a single repairman. The following assumptions are made. Component failure and repair times are independent, exponentially distributed, random variables. Component failures can occur even while the system is not functioning and it is possible to reassign the repairman among failed components instantaneously. It is shown that the policy which always assigns the repairman to the failed component with the smallest failure rate among the failed ones maximizes the expected discounted system operation time irrespective of the values of the repair rates and the discount rate     

A general model for consecutive-k-out-of-n: F repairable system with exponential distribution and (k−1)-step Markov dependence

In this paper, a general model for consecutive-k-out-of-n: F repairable system with exponential distribution and (k−1)-step Markov dependence is introduced. The lifetime of a component is an exponential random variable, its parameter depends on the number of consecutive failed components that precede the component. The repair time is also an exponential random variable. A priority repair rule on the basis of the system failure risk is adopted. Then the transition density matrix of the system is determined. Some reliability indices, including the system availability, rate of occurrence of failures and reliability are evaluated accordingly. For the demonstration of the model and methodology, a linear system example and a circular system example are investigated.     

Reliability analysis of a k-out-of-n:G repairable system with single vacation

This paper analyzes a k-out-of-n:G   repairable system with one repairman who takes a single vacation, the duration of which follows a general distribution. The working time of each component is an exponentially distributed random variable and the repair time of each failed component is governed by an arbitrary distribution. Moreover, we assume that every component is “as good as new” after being repaired. Under these assumptions, several important reliability measures such as the availability, the rate of occurrence of failures, and the mean time to first failure of the system are derived by employing the supplementary variable technique and the Laplace transform. Meanwhile, their recursive expressions are obtained. Furthermore, through numerical examples, we study the influence of various parameters on the system reliability measures. Finally, the Monte Carlo simulation and two special cases of the system which are (n-1)$(n-1)$-out-of-n:G repairable system and 1-out-of-n:G repairable system are presented to illustrate the correctness of the analytical results.     

Optimal burn-in for maximizing reliability of repairable non-series systems

Burn-in is a manufacturing process applied to products to eliminate early failures in the factory before the products reach the customers. Various methods have been proposed for determining an optimal burn-in time of a non-repairable system or a repairable series system, assuming that system burn-in improves all components in the system. In this paper, we establish the trade-off between the component reliabilities during system burn-in and develop an optimal burn-in time for repairable non-series systems to maximize reliability. One impediment to expressing the reliability of a non-series system is in that successive failures during system burn-in cannot be described precisely because a failed component is not detected until the whole system fails. For approximating the successive failures of a non-series system during system burn-in, we considered two types of repair: minimal repair at the time of system failure, and repair at the time of component or connection failure. The two types of repair provide bounds on the optimal system burn-in time of non-series systems.     

有两种故障状态的两部件串联系统的预防维修策略

本文研究的是由两个部件串联组成且有两种故障状态的系统的预防维修策略, 当系统的工作时间达到T时进行预防维修, 预防维修使部件恢复到上一次故障维修后的状态。每个部件发生故障都有两种状态, 可维修和不可维修。当部件的故障为可维修故障时, 修理工对其进行故障维修, 且每次故障维修后的工作时间形成随机递减的几何过程, 每次故障后的维修时间形成随机递增的几何过程。当部件发生N次可维修故障或一次不可维修故障时进行更换。以部件进行预防维修的间隔和更换前的可维修故障次数N组成的二维策略(T, N) 为策略, 利用更新过程和几何过程理论求出了系统经长期运行单位时间内期望费用的表达式, 并给出了具体例子和数值分析。