ISSN:0039-0402    

DOI:10.1111/j.1467-9574.1990.tb01274.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

We present an asymptotically optimal Bayesian learning procedure for the (s, Q) inventory policy, for the case when the probability distribution of lead time demand is unknown. This distribution is not required to be a member of a certain family, and the maximal lead time demand is also allowed to be unknown. The algorithm developed for this purpose Is an extension of a standard iterative procedure, which in its original form ‐in spite of claims to the contrary‐might produce solution values that are arbitrarily far away from the optimal

ISSN:0039-0402    

DOI:10.1111/j.1467-9574.1990.tb01275.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

We address the problem of schedulingnidentical jobs on m uniform parallel machines to optimize scheduling criteria that are nondecreasing in the job completion times. It is well known that this can be formulated as a linear assignment problem, and subsequently solved inO(n3) time. We give a more concise formulation for minsum criteria, and show that general minmax criteria can be minimized inO(n2) time. We present faster algorithms, requiring onlyO(n+mlogm) time for minimizing makespan and total completion time,O(nlogn) time for minimizing total weighted completion time, maximum lateness, total tardiness and the weighted number of tardy jobs, andO(nlog2n) time for maximum weighted tardiness. In the case of release dates, we propose anO(nlogn) algorithm for minimizing makespan, and anO(mn2m+1) time dynamic programming algorithm for minimizing total completion time.

ISSN:0039-0402    

DOI:10.1111/j.1467-9574.1990.tb01276.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

In this paper we present a model which unifies several existing models with respect to two phases of the planning process of a Flexible Manufacturing System. These phases are the system setup phase and the scheduling phase and in literature they usually are considered separately. We give a mathematical formulation encompassing both phases. From this formulation several existing approaches can be deduced. We also describe some heuristic methods for our model and present the computational results.

ISSN:0039-0402    

DOI:10.1111/j.1467-9574.1990.tb01277.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

In the early eighties, Fisher and Jaikumar developed a generalized assignment heuristic for vehicle routing problems. In this paper, we discuss some of the strong and weak points of this heuristic, and take its basic ideas to develop a new parallel insertion heuristic for the vehicle routing and scheduling problem that is better able to handle various side constraints.

ISSN:0039-0402    

DOI:10.1111/j.1467-9574.1990.tb01278.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

In this paper, we study inventory control problems arising in multi‐echelon production/distribution chains. In these chains, material is delivered by outside suppliers, proceeds through a number of manufacturing stages, and is distributed finally among a number of local warehouses in order to meet market demand. Each stage requires a fixed leadtime; furthermore, we assume a stochastic, stationary end‐item demand process.The problem to balance inventory levels and service degrees can be modelled and analyzed by defining appropriate cost functions. Under an average cost criterion, we study the three most important structures arising in multi‐echelon systems: assembly systems, serial systems and distribution systems. For all three systems, it is possible to prove exact decomposition results which reduce complex multi‐dimensional control problems to simple one‐dimensional problems. In addition, we establish the optimality of base‐stock contr

ISSN:0039-0402    

DOI:10.1111/j.1467-9574.1990.tb01279.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

ISSN:0039-0402    

DOI:10.1111/j.1467-9574.1990.tb01280.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY