摘要:

AbstractThe theory of the control of stock is well understood, and a large number of firms use automatic stock control and ordering techniques as a major part of their inventory control systems. However, the effectiveness of such automatic stock control systems depends on the correct selection of system parameters for each item in the inventory and on the accurate reporting of information. It is not unusual for errors to be made in both the selection of parameters and the entry of data, and regular failures of either can cause severe problems in stock control. It is generally difficult for a human stock controller to discover errors quickly because of the large number of items that is usually found in a company inventory. This paper describes the use of an expert system to examine stock records and diagnose anomalies in the data provided or parameters applied to individual items in a stock control system. The expert system‘reasons’from symptoms such as reports from the forecasting system or high stock levels, to defects in the stock model used or data-collection processes, and from there to possible remedial action. Results are presented for runs of the expert system on a simulated stock control system.

ISSN:0160-5682    

DOI:10.1057/jors.1989.167

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractOver the years, various methods and models for the assessment of management potential have been developed. A large financial institution uses an assessment centre to determine management potential of existing staff, and information collected from the various activities carried out at the centre is used to produce an overall rating of potential. The way in which this rating is determined is examined, and it is felt that a more effective method of using the information can be developed. In order to do this, a scientific approach to the analysis of the information already collected was adopted. From the results of the analysis, and with due consideration to the non-quantitative aspects of the situation, models for determining management potential can be developed.

ISSN:0160-5682    

DOI:10.1057/jors.1989.168

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractIn this paper, an inventory oxygen-bottles problem is formulated as (i) an (M/M/C):(GD/N/∞) queueing model with different service rates; (ii) a probabilistic goal programming (PGP) model. By using the first model, the optimum required rate for oxygen bottles to be stored is determined. By using the second model, the decision-maker can determine his policy, which minimizes the total cost. Finally, a case study of the storage of oxygen bottles for the Egyptian Air Force (1980-1984) is presented.

ISSN:0160-5682    

DOI:10.1057/jors.1989.169

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractA 0-1 integer linear programme for the selection and scheduling of US National Aeronautics and Space Administration (NASA) missions over a long planning horizon is presented. This model was formulated to allow a higher-level user-interaction with an advanced missions database currently being developed. The model implicitly considers the multi-objective nature of the problem, which results from the desire to maximize benefits in several categories as well as from the desire to minimize cost. In addition, the model allows the planner much flexibility in the selection process. This is accomplished by allowing the planner the ability to specify long- or short-term budget constraints, precursor/follow-on mission requirements, or any number of other idiosyncratic constraints which might be of importance in the decision process. Small example problems are solved in order to illustrate the approach, and areas for further research are discussed.

ISSN:0160-5682    

DOI:10.1057/jors.1989.170

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractThe context is that of a retail chain where stock is purchased into a central warehouse from which branch stocks are replenished. This paper considers possible methods of allocating limited warehouse stock to branches, and uses simulation to quantify the resulting benefits.

ISSN:0160-5682    

DOI:10.1057/jors.1989.171

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractBy describing the industrial assembly of a real product, methodologies and considerations are discussed for the re-alignment of discrete assembly systems in line with modern standards. Poor manufacturing procedures are highlighted, and a number of alternative strategies for system replacement are presented. A decision tree is used to categorize assembly into one of three types, and an integrated solution is proposed. The possible financial benefits, essential to maintain market position, are identified for each stage of an evolutionary cycle of continuous product design and changing manufacturing methods.

ISSN:0160-5682    

DOI:10.1057/jors.1989.172

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractThis paper describes a case study in which a simulation model, specifically an attraction-constrained spatial interaction model, is used to provide information to assist in the exploration of different options for the future provision of in-patient hospital facilities in an English Regional Health Authority. The model is used to evaluate options on the basis of their effect on two different criteria: first the level of utilization of hospital in-patient facilities relative to need of populations resident in different parts of the region, and secondly the relative ease of geographical access of the facilities to the populations served.

ISSN:0160-5682    

DOI:10.1057/jors.1989.173

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractThis problem deals with the location of a route or path through a set of given points in order to maximize the smallest weighted distance from the given points to the route. Applications may include the planning of pipelines carrying noxious material, and also certain problems in robotics. The first algorithm finds a non-linear path by iteratively solving network minimal-cut problems. A second algorithm solves the case where the route is restricted to be linear.

ISSN:0160-5682    

DOI:10.1057/jors.1989.174

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractThis paper discusses a new formulation of a class of plant product-mix loading problems which are characterized by capacitated production facilities, demand fill-rate requirements, fixed facility costs, concave variable production costs and an integrated network structure which encompasses inbound supply and outbound distribution flows. In particular, we are interested in assigning product lines and volumes to a set of capacitated plants under the demand fill-rate constraints. Fixed costs are incurred when a product line is assigned to a plant. The variable production-cost function also exhibits concavity with respect to each product-line volume. Thus both scale economies and plant focus effect are considered explicitly in the model. The model also can be used to determine which market to serve in order to best allocate the firm's resources. The problem formulation leads to a concave mixed-integer mathematical programme. Given the state of the art of non-linear programming techniques, it is often not possible to find global optima for reasonably sized problems. We develop an optimization algorithm within the framework of Benders' decomposition for the case of a piecewise linear concave cost function. Our algorithm generates optimal solutions efficiently.

ISSN:0160-5682    

DOI:10.1057/jors.1989.175

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractIn an era of declining and fluctuating enrolments, the determination of appropriate school sizes and student assignments poses difficult problems for administrators. For two decades, researchers have worked with variants of a linear programming districting model which minimizes total weighted distance as all students are assigned to schools constrained by both capacity and racial balance limitations. This model could aid in the generation of districting alternatives, but is difficult to solve in realistic applications with generalized solution procedures because of overall problem size. This has prompted the development of fast, network-based models, solvable with special algorithms and codes. We show, however, that these approaches all contain major shortcomings. We present a fast, hybrid heuristic based upon two network representations. Computational results demonstrate this to be a very fast solution approach for the general case of this districting problem.

ISSN:0160-5682    

DOI:10.1057/jors.1989.176

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor