摘要:

Data Envelopment Analysis (DEA) is a mathematical programming approach to assessing relative efficiencies within a group of Decision Making Units (DMUs). An important outcome of such an analysis is a set of virtual multipliers or weights accorded to each (input or output) factor taken into account. These sets of weights are, typically, different for each of the participating DMUs. A version of the DEA model is offered where bounds are imposed on weights, thus reducing the variation in the importance accorded to the same factor by the various DMUs. Techniques for locating appropriate bounds are suggested and the notion of a common set of weights is examined. Possible interpretations to differences in efficiency ratings obtained with the various models developed are discussed.

ISSN:0740-817X    

DOI:10.1080/07408179108963835

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

This paper considers new flowshop scheduling problems related to automated manufacturing systems in whichnjobs are processed on two machinesMaandMbin this order. The job transportation between two machines is done by a single automated guided vehicle (AGV), and is crucial because no machine has buffer storage for work-in-process (WIP) and hence a machine cannot release a finished job until the empty AGV becomes available at that machine, while the AGV cannot transfer an unfinished job to a machine until the machine is empty. O(n3) algorithms are given in this paper to find optimal sequences ofnjobs that minimize their maximum completion time (i.e., makespan). Some numerical results are also given to evaluate the effect of computing optimal sequences.

ISSN:0740-817X    

DOI:10.1080/07408179108963836

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Making optimal price-inventory decisions in the face of alternate criteria is studied for a monopoly firm. When the firm's demand function belongs to the logarithmic concave class, necessary and sufficient optimality conditions are obtained for profit and return on inventory investment criteria. It is shown that decentralized price-inventory decision-making is optimal when the return criterion is used. The theoretical developments are elucidated with a detailed study of linear demand and a comprehensive numerical example.

ISSN:0740-817X    

DOI:10.1080/07408179108963837

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The classical economic order quantity (EOQ) model assumes that items produced are of perfect quality and that die unit cost of production is independent of demand. Product quality is not always perfect but directly affected by the reliability of the production process used to produce the products. In addition, a relationship between unit production cost and demand may exist under certain circumstances. We propose an EOQ model with demand-dependent unit production cost and imperfect production processes. We formulate this inventory decision problem as a geometric program (GP) and solve it to obtain closed-form optimal solutions. An illustrative example is provided to demonstrate the point that GP has potential as a valuable analytical tool for studying a certain class of inventory control problems. We also discuss the aspect of sensitivity analysis based on the GP approach.

ISSN:0740-817X    

DOI:10.1080/07408179108963838

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

While all previous research on the newsboy problem considered the single-product case, a recently published paper studied a two-product newsboy problem under the objective of maximizing the probability of achieving a profit target. Numerical solutions to this problem reveal some very intriguing properties, but little analytical results were obtained. This paper presents an analytical solution procedure to the problem for the case of exponentially distributed independent demands. Our analytical structure reveals even more intriguing properties, and confirms that the multiproduct extension of the newsboy problem is a very challenging and fruitful research area.

ISSN:0740-817X    

DOI:10.1080/07408179108963839

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

A stochastic model for a screening program is presented in which the natural history of the disease is assumed to progress through a set of stages before detection. A model of the whole process is developed to address the interaction of the disease process and screening process. The purpose of the model is to develop insight into the disease process and derive policies which are optimal relative to the particular objectives chosen.

ISSN:0740-817X    

DOI:10.1080/07408179108963840

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

In survey sampling, estimating the total for a finite population is a common objective. In power systems load research, as in many other survey sampling applications, the totals of several finite populations must be estimated from the same sample. While the sampling plan may be optimal for estimating one parameter, it is likely not to be optimal for estimating all parameters of interest. Thus a common strategy in such cases is to choose estimators for the other parameters of interest having minimum mean square error (mse) for the selected sampling plan.

ISSN:0740-817X    

DOI:10.1080/07408179108963841

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Automated Guided Vehicle (AGV) systems continue to play a significant role in many low to medium flow manufacturing operations, including Flexible Manufacturing Systems (FMS) and other applications. The relatively inexpensive guidepath, coupled with the high degree of flexibility and control offered in vehicle routing, has made AGV systems a proven and viable handling technology for the 90's.

ISSN:0740-817X    

DOI:10.1080/07408179108963842

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

This paper provides a unified framework in which product and process demands can be related to manufacturing system requirements. A nonlinear cost minimization model is developed that can be used by facility planners to guide the analyses underlying the equipment selection problem. The approach extends current work by accounting for machine flexibility. The objective is to determine how many of each machine type to purchase, as well as what fraction of the time each piece of equipment will be configured for a particular type of operation.

ISSN:0740-817X    

DOI:10.1080/07408179108963843

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The purpose of this paper is to provide a basis for locating product in an order picking warehouse such that average order picking time will be minimized. A stochastic model is developed to ensure that optimal, rather than just “good,” results are obtained. It is shown that, for a class of order picking warehouse, simple, but general, assignment algorithms may be used to optimally allocate product to locations. The results are then used to explore the effects of average order size and the shape of the inventory curve on order picking efficiency.

ISSN:0740-817X    

DOI:10.1080/07408179108963844

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor