摘要:

AbstractThe fleet warranty guarantees the purchaser of a large population of like items that the mean life of the fleet will meet or exceed some negotiated mean μL. If the mean life is less than μL, compensation may be given in terms of a number of free replacement partsR. The expected number of replacementsE[R]is studied based upon how the mean life of items in the field is determined and on whether the sampling window starts at timet= 0 (ordinary renewal process) or at some arbitrarily large timew(equilibrium renewal process). Properties ofE[R]are compared and examples are given. © 1994 John Wiley&Sons, I

ISSN:0894-069X    

DOI:10.1002/1520-6750(199406)41:4<465::AID-NAV3220410402>3.0.CO;2-8

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractConsider the problem of estimating the reliability of a series system of (possibly) repairable subsystems when test data and historical information are available at the component, subsystem, and system levels. Such a problem is well suited to a Bayesian approach. Martz, Waller, and Fickas [Technometrics,30, 143–154 (1988)] presented a Bayesian procedure that accommodates pass/fail (binomial) data at any level. However, other types of test data are often available, including (a) lifetimes of nonrepayable components, and (b) repair histories for repairable subsystems. In this article we describe a new Bayesian procedure that accommodates pass/fail, life, and repair data at any level. We assume a Weibull model for the life data, a censored Weibull model for the pass/fail data, and a power‐law process model for the repair data. Consequently, the test data at each level can be represented by a two‐parameter likelihood function of a certain form, and historical information can be expressed using a conjugate family of prior distributions. We discuss computational issues, and use the procedure to analyze the reliability of a vehicle system. © 1994 John Wiley&Son

ISSN:0894-069X    

DOI:10.1002/1520-6750(199406)41:4<483::AID-NAV3220410403>3.0.CO;2-1

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractThe purpose of this research is to investigate simulation algorithms for nonhomogeneous Poisson processes with proportional intensities. Two algorithmic approaches are studied: inversion and thinning. Motivated by industrial practices, the covariate vector involved in the simulation is permitted to change after every event (or observation). The algorithms are extended to permit the simulation of general nonhomogeneous Poisson processes with possible discontinuities both in baseline intensity and covariate vector. This latter extension can be used to facilitate a wide range of failure situations that can arise with repairable systems. © 1994 John Wiley&Sons, Inc

ISSN:0894-069X    

DOI:10.1002/1520-6750(199406)41:4<507::AID-NAV3220410404>3.0.CO;2-H

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractAn economic sequential screening procedure is considered for limited failure populations in which defective items fail soon after they are put in operation and nondefective ones never fail during the technical life of the items. A cost model is constructed that involves screening test cost and external failure cost. A sequential scheme that minimizes the expected cost is derived from the solution of a dynamic programming formulation and the optimal decision at each stage is obtained in a closed form. © 1994 John Wiley&Sons, Inc

ISSN:0894-069X    

DOI:10.1002/1520-6750(199406)41:4<523::AID-NAV3220410405>3.0.CO;2-C

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractThe discrete failure rate model that has a change point is considered. A strongly consistent estimator for the change point is obtained. This produces consistent estimators for the failure rate and survival functions that converge uniformly with probability 1. © 1994 John Wiley&Sons, Inc

ISSN:0894-069X    

DOI:10.1002/1520-6750(199406)41:4<537::AID-NAV3220410406>3.0.CO;2-2

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractA stochastic optimization model for capacity expansion for a service industry that incorporates uncertainty in future demand is developed. Based on a weighted set of possible demand scenarios, the model generates a recommended schedule of capacity expressions, and calculates the resulting sales under each scenario. The capacity schedule specifies the size, location, and timing of these expansions that will maximize the company's expected profit. The model includes a budget constraint on available resources. By using Lagrangian relaxation and exploiting the special nested knapsack structure in the sub‐problems, an algorithm was developed for its solution. Based on the initial computational results, this algorithm appears to be more efficient than linear programming for this special problem. © 1994 John Wiley&Sons, I

ISSN:0894-069X    

DOI:10.1002/1520-6750(199406)41:4<545::AID-NAV3220410407>3.0.CO;2-Z

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractThis article presents a new approach to solve the problem of coordinating the overhaul scheduling of several nonidentical production units. For each production unit, we assume that the operating cost is ann‐order polynomial function of the time elapsed since its previous overhaul. We develop an efficient iterative algorithm that generates a near‐optimal cyclic overhaul schedule. We also construct a simple algorithm for the case where the overhaul interval for each production unit and the cycle time are restricted to be power‐of‐two multiples of some base planning period. Finally, we provide a worst‐case performance bound for the solution to the problem under the power‐of‐two restriction. © 1994 John W

ISSN:0894-069X    

DOI:10.1002/1520-6750(199406)41:4<565::AID-NAV3220410408>3.0.CO;2-Q

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractIn this note we consider the familiar bin‐packing problem and provide new worst‐case results for a number of classical heuristics. We show that the first‐fit and best‐fit heuristics have an absolute performance ratio of no more than 1.75, and first‐fit decreasing and best‐fit decreasing heuristics have an absolute performance ratio of 1.5. The latter is the best possible absolute performance ratio for the bin‐packing problem, unless P = NP. © 1994 John W

ISSN:0894-069X    

DOI:10.1002/1520-6750(199406)41:4<579::AID-NAV3220410409>3.0.CO;2-G

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

ISSN:0894-069X    

DOI:10.1002/1520-6750(199406)41:4<::AID-NAV3220410401>3.0.CO;2-R

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY