摘要:

AbstractThe proposed method analyses system behaviour as described through time-series nominal data. Time relationships are explicitly considered, as are the effects of previous behaviour on later behaviour (memory). Probabilistic estimates are generated for future time-periods.

ISSN:0160-5682    

DOI:10.1057/jors.1986.195

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

AbstractA multi-item inventory system is considered which has the property that, for each single item, a reorder policy using the E.O.Q. formula would be appropriate. Holding costs are linear, and fixed ordering costs are assumed to be composed of a major set-up cost reflecting the pure fact of placing an order, and a sum of minor set-up costs corresponding to the items included in the order. If it is desirable to form a certain number of groups of items where all items of one group share the same order cycle, it is shown that there is always an optimal grouping in which items are arranged in increasing order of their ratio of yearly holding costs and minor set-up costs.A heuristic for forming the groups is given which turns out to be an optimal algorithm for the case that there are no major set-up costs. After an initial sorting of ratios, the worst-case complexity of this procedure is linear in the number of items.

ISSN:0160-5682    

DOI:10.1057/jors.1986.196

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

AbstractUntil recently, the majority of models used to find an optimal sequence for the standard flow-shop problem were based on a single objective, typically makespan. In many applications, the practitioner may also want to consider other criteria simultaneously, such as mean flow-time or throughput time. As makespan and flow-time are equivalent criteria for optimizing machine idle-time and job idle-time, respectively, these additional criteria could be inherently considered as well. The effect of job idle-time, measuring in-process inventory, could be of particular importance.This paper presents an extension of an earlier model developed by the authors, formulating the generalizedNjob,Mmachine standard flow-shop problem as a mixed-integer goal-programming model. The formulation was empirically tested through a comparison of the generated optimal solutions to their mathematically derived counterparts. For this, a special flow-shop problem with certain permutation properties was selected. In addition, a randomly chosen problem was solved to show the general applicability of the derived formulation.The model allows the incorporation of the makespan as well as the mean flow-time criteria, instead of optimization being based on a single objective.

ISSN:0160-5682    

DOI:10.1057/jors.1986.197

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

AbstractIn this paper, the Weber problem is considered. We demonstrate how the three existing points may be simultaneously tested for optimality by means of a simple geometrical construction.

ISSN:0160-5682    

DOI:10.1057/jors.1986.198

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

AbstractIn manpower planning, it is essential to be able to monitor stability of the length-of-service structure of the staff. Such a stability index is provided by the formula for entropy of a continuous distribution, evaluated for length of service. This measure improves on the previous discrete version by removing the necessity of introducing arbitrary tenure classes, thus facilitating inter-company comparisons. It is closely related to the entropy formula used in demography, and manpower planners may therefore avail themselves of results already used by demographers.

ISSN:0160-5682    

DOI:10.1057/jors.1986.199

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

ISSN:0160-5682    

DOI:10.1057/jors.1986.200

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

ISSN:0160-5682    

DOI:10.1057/jors.1986.201

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

ISSN:0160-5682    

DOI:10.1057/jors.1986.202

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

ISSN:0160-5682    

DOI:10.1057/jors.1986.203

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

ISSN:0160-5682    

DOI:10.1057/jors.1986.204

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor