Showing papers in "Journal of the Operational Research Society in 1993"
TL;DR: This new edition of Toyota Production System: An Integrated Approach to Just-In-Time updates the classic with new material on e-kanban, mini-profit centers, computer-based information systems, and innovative solutions to common obstacles in TPS implementation.
Abstract: The Toyota production System is a technology of comprehensive production management the Japanese invented a hundred years after opening up to the modern world. More than likely, another gigantic advance in production methods will not appear for some time to come.
1,674 citations
TL;DR: In this article, the optimality of Scarf's ordering rule for the newsboy problem with only the mean and the variance of the demand are known is analyzed, and the analysis is extended to the fixed ordering cost case, where a fixed cost is charged for placing an order, and to the case of random yields.
Abstract: We present here a new, very compact, proof of the optimality of Scarf's ordering rule for the newsboy problem where only the mean and the variance of the demand are known. We then extend the analysis to the recourse case, where there is a second purchasing opportunity; to the fixed ordering cost case, where a fixed cost is charged for placing an order; to the case of random yields; and to the multi-item case, where multiple items compete for a scarce resource.
762 citations
TL;DR: In this paper, the authors present Shaping the Future: Business Design Through Information Technology, a survey of the state-of-the-art technologies in the field of information technology.
Abstract: (1993). Shaping the Future: Business Design Through Information Technology. Journal of the Operational Research Society: Vol. 43, No. 9, pp. 1249-1250.
512 citations
340 citations
TL;DR: This paper reviews CMS’s progress, main themes, theoretical and epistemological premises, and main projects; it also identifies some problems Tight_G_UN#_Master.indd.
Abstract: Critical management studies (CMS) offers a range of alternatives to mainstream management theory with a view to radically transforming management practice. The common core is deep skepticism regarding the moral defensibility and the social and ecological sustainability of prevailing conceptions and forms of management and organization. CMS’s motivating concern is neither the personal failures of individual managers nor the poor management of specific firms, but the social injustice and environmental destructiveness of the broader social and economic systems that these managers and firms serve and reproduce. This paper reviews CMS’s progress, main themes, theoretical and epistemological premises, and main projects; we also identify some problems Tight_G_UN#_Master.indd 1 8/1/07 10:02:33 AM 2 • LeftRunningHead © 2007 Taylor & Francis Group, LLC and make some proposals. Our aim is to provide an accessible overview of a growing movement in management studies.
276 citations
TL;DR: In this paper, the main role of the facilitator in a group is seen as contributing to process and structure, not content, and the facilitators main tasks are to see and understand the group life, intervening only to help the group maintain a task orientation to its work.
Abstract: This paper concerns the facilitation of working groups whose general aims are to achieve a shared understanding of issues, a sense of common purpose and a mutual commitment to action. We see the main role of the facilitator in such a group as contributing to process and structure, not content. This view is coloured by our assumptions about groups and how their work can be facilitated: that groups have an emotional life which influences and is influenced by each participant who experiences a tension between what is best for the group and what is personally desired, and that the facilitator's main tasks are to see and understand the group life, intervening only to help the group maintain a task orientation to its work. To understand the group the facilitator observes verbal and non-verbal behaviour, attends to relationships between participants and maintains awareness of his or her own feelings. For some work groups, the facilitator can be helped by computers, which provide an effective means externalizing many aspects of group work. By assigning to the computer the information manipulation and communication tasks, group members can concentrate their attention on the judgmental tasks, and the facilitator can attend better to group processes. Effectively used, computers can help a group maximize the creative and minimize the destructive aspects of its life.
267 citations
TL;DR: It is found that, in general, data envelopment analysis outperforms regression analysis on accuracy of estimates but regression analysis offers greater stability of accuracy.
Abstract: This paper compares regression analysis and data envelopment analysis as two alternative methods for assessing the comparative performance of homogeneous organizational units such as bank branches or schools The comparison is restricted to units using a single resource or securing a single output It focuses on the estimates of relative efficiency, marginal input-output values and target input-output levels that the two methods offer A set of hypothetical hospitals is used to illustrate the performance of the two methods It is found that, in general, data envelopment analysis outperforms regression analysis on accuracy of estimates but regression analysis offers greater stability of accuracy
222 citations
TL;DR: A collection of papers on the application of Markov decision processes is surveyed and classified according to the use of real life data, structural results and special computational schemes.
Abstract: A collection of papers on the application of Markov decision processes is surveyed and classified according to the use of real life data, structural results and special computational schemes. Observations are made about various features of the applications.
215 citations
TL;DR: In this article, the authors compare the ANN method with the Discriminant Analysis (DA) method in order to understand the merits of ANN that are responsible for the higher level of performance.
Abstract: Artificial Neural Network (ANN) techniques have recently been applied to many different fields and have demonstrated their capabilities in solving complex problems. In a business environment, the techniques have been applied to predict bond ratings and stock price performance. In these applications, ANN techniques outperformed widely-used multivariate statistical techniques. The purpose of this paper is to compare the ANN method with the Discriminant Analysis (DA) method in order to understand the merits of ANN that are responsible for the higher level of performance. The paper provides an overview of the basic concepts of ANN techniques in order to enhance the understanding of this emerging technique. The similarities and differences between ANN and DA techniques in representing their models are described. This study also proposes a method to overcome the limitations of the ANN approach, Finally, a case study using a data set in a business environment demonstrates the superiority of ANN over DA as a method of classification of observations.
197 citations
TL;DR: In this paper, a participatory research project carried out within a local level public organization, concerned with developing a strategy for collaboration with other organizations, is described, and two concepts are introduced, "collaborative advantage" and "shared meta-strategy".
Abstract: This paper is based upon a participatory research project carried out within a local level public organization, concerned with developing a strategy for collaboration with other organizations. Two concepts are introduced, ‘collaborative advantage’ and ‘shared meta-strategy’. The issues surrounding these, which have arisen in the course of the project, are discussed and related to other literature in the area. It is argued that these two concepts, and the associated issues, may be helpful to others wishing to collaborate. However, they should be regarded as a basis for discussion and reinterpretation in the context of any particular collaboration.
191 citations
TL;DR: This paper describes an approach derived from the integration of data envelopment analysis and a multi-attribute value function that overcomes some of the limitations of the original DEA approach and increases users' understanding of DEA.
Abstract: Both Data Envelopment Analysis (DEA) and Multiple Criteria Analysis (MCA) can be used to assess the efficiency with which units perform similar tasks. This paper describes an approach derived from the integration of data envelopment analysis and a multi-attribute value function. This approach is implemented as a visual interactive decision support system, the use of which is illustrated by a practical application. The authors feel that this approach overcomes some of the limitations of the original DEA approach and, in particular, increases users' understanding of DEA. The approach is particularly well suited to the analysis of the efficiency of a small number of units.
TL;DR: Three simple heuristics for the vehicle routeing problem with customer time windows that can be violated by paying appropriate penalties are described, which enables significant reduction in the number of vehicles required and/or the total route distances while controlling both customer penalties and waiting times.
Abstract: We describe three simple heuristics for the vehicle routeing problem with customer time windows that can be violated by paying appropriate penalties. The customer demands are known, and a homogeneous fleet of vehicles stationed at a single depot is considered. The penalty payable to a customer is assumed to be a linear function of the amount of time window violation. Upper limits are imposed on both the penalty payable and the waiting time allowed at any customer. At each customer in a route, the PC-based heuristics simultaneously determine the actual time to begin service, and the next customer to serve. To achieve this, each heuristic uses different measures to compare the cost of waiting and penalty payable, with the benefit obtained by leaving immediately for the next customer. Computational results on a set of benchmark problems show that the procedure is efficient and enables significant reduction in the number of vehicles required and/or the total route distances while controlling both customer penalties and waiting times.
TL;DR: A procedure is presented for incorporating an ordinal factor into the DEA structure, with the resulting formulation being a particular form of cone ratio model, which is then applied to the technology installation efficiency problem.
Abstract: In many problems involving efficiency analysis using DEA, certain factors may be measurable only on an ordinal scale. Specifically, it may be possible only to rank order the DMUs according to a factor, rather than being able to assign a specific numerical value of that factor to each DMU. To illustrate this, we examine a problem involving the evaluation of new technology installations. The presence of qualitative factors in such an environment motivates the need to investigate how such factors can be incorporated into existing efficiency measurement models. In particular, a procedure is presented for incorporating an ordinal factor into the DEA structure, with the resulting formulation being a particular form of cone ratio model. The model is then applied to the technology installation efficiency problem.
TL;DR: A genetic algorithm to solve the Steiner Minimal Tree problem in graphs with standard set of graph problems used extensively in the comparison of Steiner tree algorithms has been solved using the resulting algorithm.
Abstract: We develop a genetic algorithm (GA) to solve the Steiner Minimal Tree problem in graphs. To apply the GA paradigm, a simple bit string representation is used, where a 1 or 0 corresponds to whether or not a node is included in the solution tree. The standard genetic operators-selection, crossover and mutation-are applied to both random and seeded initial populations of representations. Various parameters within the algorithm have to be set and we discuss how and why we have selected the values used. A standard set of graph problems used extensively in the comparison of Steiner tree algorithms has been solved using our resulting algorithm. We report our results (which are encouragingly good) and draw conclusions.
TL;DR: A basic introduction to the ideas of Tabu search is given, and some computational experiments on TS are reported, which tend to confirm the general opinion that when implemented efficiently, TS is a more effective search paradigm than SA.
Abstract: Tabu search (TS) is becoming increasingly recognized as an efficient way of finding high-quality solutions to hard combinatorial problems. It may be described as an intelligent meta-heuristic for controlling simpler local search procedures. However, reported applications have often used a ‘brute-force’ approach without considering the most effective use of the computing effort available. This paper intends firstly to give a basic introduction to the ideas of TS, and then it will report some computational experiments on TS in the context of machine sequencing. These have shown that it is important to define the balance between exploration of the solution space and exploitation of the information obtained. The results will be compared with those obtained from a proven Simulated Annealing (SA) algorithm, which tends to confirm the general opinion that when implemented efficiently, TS is a more effective search paradigm than SA.
TL;DR: Several heuristics are presented for the flowshop scheduling problem with the objective of minimizing mean tardiness, and the various methods that have been devised for minimizing the makespan are modified for this objective.
Abstract: Several heuristics are presented for the flowshop scheduling problem with the objective of minimizing mean tardiness. We consider the cases in which job sequences on all machines are the same (permutation flowshop) and in which they may be different. For the former case, the various methods that have been devised for minimizing the makespan are modified for our objective, while the list scheduling algorithm is used for the latter case. These heuristics are tested and compared with each other on randomly-generated test problems.
TL;DR: It is shown that ordering policy at the warehouse is a function of how goods are distributed to lower echelons and that coordination leads to cost reduction.
Abstract: This paper addresses a multiperiod integrated model that plans deliveries to customers based upon inventories (at warehouse and customer locations) and vehicle routes. The model determines replenishment quantities and intervals at the warehouse, and distribution lots and delivery routes at customer locations. We investigate coordination of customer and warehouse replenishment decisions and illustrate their interdependence. Computational experience on randomly generated problems is reported. We show that ordering policy at the warehouse is a function of how goods are distributed to lower echelons and that coordination leads to cost reduction.
TL;DR: A heuristic model is developed to determine the optimal times for inventory replenishment whether or not a planning horizon exists and some numerical examples are given.
Abstract: The classical no-shortage inventory policy is examined for the case of deteriorating items having a deterministic demand pattern with a linear (positive) trend A heuristic model is developed to determine the optimal times for inventory replenishment whether or not a planning horizon exists Some numerical examples are given
TL;DR: In this paper, the key to successful total quality management is to create culture change: The Key to Successful Total Quality Management (TQM) is discussed. Journal of the Operational Research Society: Vol. 44, No. 5, pp. 525-526.
Abstract: (1993). Creating Culture Change: The Key to Successful Total Quality Management. Journal of the Operational Research Society: Vol. 44, No. 5, pp. 525-526.
TL;DR: By extending the definition of a petal route, more general forms of vehicle route can be generated without invalidating the important underlying property that optimal petal solutions can be produced very easily.
Abstract: The petal method for vehicle routeing imposes special structure on the form of a feasible route. In this paper we show that by extending the definition of a petal route, more general forms of vehicle route can be generated without invalidating the important underlying property that optimal petal solutions can be produced very easily. It will also be shown that the optimal generalized petal solution can be produced efficiently by multiple applications of a shortest path algorithm.
TL;DR: An investigation was conducted into the spreadsheet practices in ten firms, with an emphasis on the process of building spreadsheet models, and showed that spreadsheet models were usually built in an informal, iterative manner, by people from all organizational levels.
Abstract: Spreadsheet models are increasingly being used in decision making within organizations. With questions about the quality of these models, an investigation was conducted into the spreadsheet practices in ten firms, with an emphasis on the process of building spreadsheet models. The study showed that spreadsheet models were usually built in an informal, iterative manner, by people from all organizational levels. These people had received very little training in the building of models, which could help explain why at least 25% of the models contained errors. Other problems were also found. It was evident that the spreadsheet practices in the firms were inadequate. There is a need for increased training as well as setting and enforcing organizational spreadsheet standards. This could provide an opportunity for OR workers if carefully handled. Although the study was viewed as exploratory, it indicated a need for further study into the effect of formal design practices on the incidence of errors and model creation time.
TL;DR: In this paper, the authors considered the joint replenishment inventory problem for N items under constant demand and proposed a solution to find the global optimum within the class of cyclic strategies, however, the algorithm of Goyal does not always lead to the optimal cyclic strategy.
Abstract: This note considers the joint replenishment inventory problem for N items under constant demand. The frequently-used cyclic strategy (T; k1, …, k N ) is investigated: a family replenishment is made every T time units and item i is included in each k i th replenishment. Goyal proposed a solution to find the global optimum within the class of cyclic strategies. However, we will show that the algorithm of Goyal does not always lead to the optimal cyclic strategy. A simple correction is suggested.
TL;DR: The purpose is to assist the development of a shared understanding of how culture, power and politics combine to affect the behaviour of a process, when subjected to externally superimposed changes in responsibility.
Abstract: This paper uses a recent application of System Dynamics in community care to contribute to a clarification of the role of System Dynamics as a framework for strategic debate A revised framework for System Dynamics within a philosophy of 'modelling as learning' is summarized This framework is now referred to as Systems Thinking and combines knowledge acquisition and both qualitative and quantitative modelling, supported by microworlds and archetypes to aid dissemination of insights The emphasis of the paper is on using qualitative models interactively with different groups of participants in the problem domain The purpose is to assist the development of a shared understanding of how culture, power and politics combine to affect the behaviour of a process, when subjected to externally superimposed changes in responsibility
TL;DR: The optimal design of a supply chain was approached in two phases by using a mathematical programming formulation and heuristic solution approach to minimize the distinct number of product types held at various points in the supply chain.
Abstract: The optimal design of a supply chain was approached in two phases by using: (1) a mathematical programming formulation and heuristic solution approach to minimize the distinct number of product types held at various points in the supply chain; and (2) a spreadsheet inventory model to estimate the safety stock needed to absorb random fluctuations in both demand and lead time throughout the system. This two-phased approach allowed management to quantify the effects of inventory required for locating parts of the supply chain in different geographic areas. The quantification of projected inventory requirements was a critical input used by senior management to clarify their final decision-making process.
TL;DR: It is shown that the two backlogs are linked in a manner that enables them to be controlled simultaneously and a procedure for dealing with incoming customer orders is presented.
Abstract: The authors are currently developing a hierarchical production planning system specifically designed for the ‘make-to-order’ sector of industry. Its aim is to control the delivery and manufacturing lead times of all orders processed by a firm. Two major decision levels are identified - the customer enquiry stage and the order release stage. Input/output control is exercised at both stages. This paper is concerned with the control mechanisms used at the customer enquiry stage. Two important backlogs of work, along with their associated backlog lengths, are identified. The system aims to maintain these backlogs between predetermined minimum and maximum lengths in order to process all orders within an acceptable length of time. It is shown that the two backlogs are linked in a manner that enables them to be controlled simultaneously. Hence, a procedure for dealing with incoming customer orders is presented.
TL;DR: Methods for calculating the most likely values of link flows in networks with incomplete data are described and a multiple probability space conditional entropy approach is described for the general network problem.
Abstract: This paper describes methods for calculating the most likely values of link flows in networks with incomplete data. The object is to present a thorough and rigorous treatment of maximum entropy flow estimation methods and to develop a methodological framework capable of handling different types of network problems. A multiple probability space conditional entropy approach is described for the general network problem. Results are presented and discussed for an example network intended for water supply.
TL;DR: The differences between modernism and postmodernism are explored, moving on to the study of language through structuralism and into poststructuralism, and some of the ideas that have inspired O(u)R practice are introduced.
Abstract: Postmodernism and poststructuralism have only been mentioned in passing within this journal. There is much more to be said, and this paper aims to open up the debate, to begin to explore the vast terrain and to present one/some agenda/s for the future, introducing some of the ideas that have inspired O(u)R practice. The paper is in four episodes. We begin by exploring the differences between modernism and postmodernism and introducing some of our sources (episode 1), moving on to the study of language through structuralism and into poststructuralism (episode 2). This section introduces some key concepts and approaches which we illustrate in a short case study (episode 3) of the language of OR. The final section (episode 4) sketches in the outlines of our future agenda. A warning is in order for people unfamiliar with postmodernism: the terminologies and style may seem unusual and untraditional for the journal.
TL;DR: Several extensions to the basic delay-time model for inspections of repairable machinery are derived, which relax earlier model assumptions, and are designed to cope with the complexities of real-world situations.
Abstract: This paper further develops the basic delay-time model for inspections of repairable machinery described in a recent paper by Baker and Wang. In our earlier work, one of a set of simple models was selected and fitted to objective data by minimizing the Akaike Information Criterion (AIC). In the present work, several extensions to the basic model are derived, which relax earlier model assumptions, and are designed to cope with the complexities of real-world situations. These extensions include allowing the age of a machine to influence both the period u from replacement of a component to visibility of a defect, and the subsequent period h to failure; allowing an inspection to have a hazardous or beneficial effect on the lifetime of a component; and allowing several mechanisms that induce a correlation between the two hitherto independent periods u and h. The resulting models were fitted to objective data, and it was found that some model extensions improved the fit for particular components. In general, we conclude that a broad range of models should be explored. This is necessary both to capture the complexity of real data, and also to give confidence in the adequacy of simpler models.