摘要:

AbstractThis paper examines experience with two decades of global model-building efforts, focusing on their impact and on methodological issues. Adopting a developing country perspective, the paper then explores what may be considered as a next stage in their evolution: the development of comprehensive policy-oriented models at the national level. The models developed at GRADE in Lima, Peru are used as an illustration of what can be achieved with national comprehensive models as policy exploration tools. The paper ends with a review of the difficulties and challenges that will be faced in the transition from global to national comprehensive models.

ISSN:0160-5682    

DOI:10.1057/jors.1990.34

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractA software engineering tool, viz. data analysis, is proposed as a method for constructing the data structures needed for software development in the field of operational research. An introduction to entity-relationship modelling is given, and the technique is applied to two areas, namely critical path analysis and simulation.

ISSN:0160-5682    

DOI:10.1057/jors.1990.35

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractWe consider the problem of determining lot sizes of multiple items that are manufactured by a single capacitated facility. The manufacturing facility may represent a bottleneck processing activity on the shop floor or a storeroom that provides components to the shop floor. Items flow from the facility to a downstream facility, where they are assembled according to a specified mix. Just-in-time (JIT) manufacturing requires a balanced flow of items, in the proper mix, between successive facilities. Our model determines lot sizes of the various items based on available capacity and four attributes of each item: demand rate, holding cost, set-up time and processing time. Holding costs for each item accrue until the appropriate mix of items is available for shipment downstream. We develop a lot-sizing heuristic that minimizes total holding cost per time unit over all items, subject to capacity availability and the required mix of items.

ISSN:0160-5682    

DOI:10.1057/jors.1990.36

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractThis paper presents a model of the two-period style-goods inventory problem for a firm which stocks many hundreds of distinctive items having heterogeneous Poisson demands. The model uses a Bayesian procedure for forecast and probability revisions based on an aggregation-by-items scheme. These revised forecasts are then incorporated into a model which is used to derive the optimal inventory-stocking policies which maximize expected profit during the season. The model is illustrated using an actual case study of inventory planning for unframed poster art.

ISSN:0160-5682    

DOI:10.1057/jors.1990.37

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractUndergraduate admissions to British universities are computerized through a central clearing house, UCCA. A by-product of this arrangement is that information on each applicant is easily available in computer-readable form. The paper describes a system used to administer undergraduate applications, forecast enrolment and do market analysis which was implemented in the Faculty of Social Sciences of Southampton University.

ISSN:0160-5682    

DOI:10.1057/jors.1990.38

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractThis paper reports on the specification of a tomato processing plant cost-function using the Schruben-Cogliano (S-C) experimental procedure for response surface identification. The method is applied to a simulation model of a tomato processing plant in order to generate a cost-function metamodel that can be used to derive conditional factor-demand equations. The results suggest that the S-C methodology provides a means of deriving conditional factor-demand equations which reduces cost-function specification error.

ISSN:0160-5682    

DOI:10.1057/jors.1990.39

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractThis paper examines a stochastic non-sequential capacitated production-planning problem where the demand of each period is a continuous random variable. The stochastic non-sequential production-planning problem is examined with sequence-independent and then with sequence-dependent set-up costs, and the worst-case error determined when an approximate solution is obtained by solving the deterministic equivalent. We prove in general that the worst-case error is not dependent on the nature of the set-up cost, and identify a family of approximations for the stochastic non-sequential production-planning problem.

ISSN:0160-5682    

DOI:10.1057/jors.1990.40

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractA special algorithm is presented for the additive model in data envelopment analysis (DEA). The special algorithm first classifies a data set into several subsets. Then the subset is solved by a different algorithmic framework. In simulation studies, the algorithm outperformed available DEA codes. The proposed algorithm can efficiently deal with a large data set.

ISSN:0160-5682    

DOI:10.1057/jors.1990.41

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractThis paper deals with a single-period, single-product inventory model. It is a multilocation problem with an opportunity for centralization. In the centralized system, the location's demands are satisfied from one central warehouse whose orders are processed on a first come, first served basis. The inventory size will be constrained to meet a specific maximum probability of being out of stock at each location. Under these assumptions, Stulman argues that a centralized system requires a lower total starting inventory than the equivalent decentralized one. We shall present a counter example showing that, under conditions where an 86% probability of stockouts is the maximum acceptable, a higher total starting inventory may be required by centralizing two locations' stock-holdings.

ISSN:0160-5682    

DOI:10.1057/jors.1990.42

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

ISSN:0160-5682    

DOI:10.1057/jors.1990.43

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor