How Relevant is Operational Research to Development? The Case of Kenyan Industry

This paper proposes that the debate over O.R.'s role in development can be advanced by looking at a specific industrial environment. The Kenyan example suggests that for O.R. to make a contribution to this developing society it must: first, be defined as broadly as possible so as to include the most basic problem-solving techniques, and second, contribute to the diffusing of these techniques throughout the economy. O.R. should be viewed less as the province of an elite group of specialists— and more as a common resource available to managers at any level of industry. O.R. educators in developing nations can "democratise" quantitative techniques by incorporating them into such traditional business disciplines as accounting, marketing, and production. These courses should stress problem-solving and rely on cases drawn from local experiences. The paper ends by describing a pilot project, the Case Research and Documentation Centre, which is designed to promote more pragmatic management education and research in Kenya.     

An Integrated Model for Master Scheduling,Lot Sizing and Capacity Requirements Planning

Although material requirements planning (M.R.P.) allows managers to better plan hierarchical production and inventory systems, much is still left to the planner's intuition and experience in devising realistic master production schedules, selecting appropriate lot sizes for components, and changing capacity levels. Decisions are made sequentially, rather than simultaneously, with no real assurance of satisfactory performance.This research proposes an integrated model for facilitating these decisions. A mixed-integer nonlinear programming model is formulated such that it can be solved by a heuristic procedure. Several versions of this procedure are tested in a research design controlling for nine variables on shop and cost structure. Preliminary research results show that the procedure gives good solutions to the situations represented by the experimental variables. Computational results are also encouraging.     

The Art of Course Planning: Soft O.R. in Action

This article is a case study described from two viewpoints: that of an analyst and that of a ‘decision-maker’. It describes the use of two ‘soft O.R.’ methods in helping the members of a university O.R. group to plan revisions to a postgraduate Diploma course, resulting in the implementation of an improved course. One author conducted the exercise while the other was a member of the client group. Given that case studies are usually written by the analyst alone, it is hoped that a client's eye-view will be useful as feedback for practitioners and can also introduce some of the concepts and terminology of soft O.R. to those engaged in more mathematical O.R. activities.     

Telephone Systems in the Third World: A Research Project

Potential users of the telephone in the Third World are often frustrated by lack of good access to the system or by its poor performance in terms of call delays. A research project has been carried out for a period of over three years addressed to the management of this ‘mess’. The field work took place in Kenya and included a major survey of telephone users in two regions. Models have been developed in the areas of regional demand and corporate policy but it is argued that these are not necessarily the major contributors to the primary goal of increased understanding. The article describes the context of the research, gives an outline of the work which has been carried out and discusses implementation. Some inferences are drawn on the usefulness of O.R. in the Third World and on research into 'messes'.     

O.R. in the National Coal Board

The organisation and philosophy of the ‘Area Service’ of the National Coal Board's Operational Research Executive is described, with special reference to factors which assist the Executive's O.R. scientists to develop good working relationships with managers.     

Real-World O.R./M.S. Applications in Journals

In this paper, we present the results of a study of real-world applications of O.R./M.S. as seen in journals. Five leading journals in the field are surveyed, and real-world application articles are classified using a two dimensional framework consisting of orientation and decision. The orientation dimension separates strategically oriented applications with long-term implications and tactically oriented applications with medium- and short-term implications. The decision dimension refers to the type of decision in the application-largely structured or largely unstructured. The major O.R./M.S. topics are placed in the resulting four quadrants, and articles published in the four most recent volumes of the five journals are classified. Based on the results of this survey, the thrust and shortcomings of implementation research are discussed. Some measures for enhancing publication of field-based research are also proposed.     

O.R. and the Systems Movement: Mappings and Conflicts

The ‘crisis’ debate in O.R. expresses concern at the divergence between textbook O.R. and what practitioners actually do. The debate is examined by comparing O.R., systems analysis and systems engineering. They are all wedded to logic in situations in which logic may not be paramount. The science in O.R. applies only to aggregate results, but the practitioner must deal with a specific situation. The tradition of systems thinking which emerged from organismic biology is described. It leads to a way out of the O.R. ‘crisis’, by providing a formal structuring of a paradigm of learning rather than optimization. O.R. can aspire to match natural science, and pass the problems by; or it can close the textbook/practitioner gap by changing its concept of ‘being scientific’.     

对使用主成分进行绩效指标值排名的讨论

对《基于数据的Goodgrant基金最优投资策略》一文使用主成分分析进行综合评价,对候选学校绩效指标值排名进行了探讨。首先,综合前人研究与本题实际,指出使用主成分分析进行综合评价存在的争议与不足;然后,分别建立TOPSIS模型和综合评价模型对候选学校的绩效指标值进行排名,并对不同方法得到的结果进行对比。结果表明,TOPSIS模型和综合评价模型得到的排名具有高度一致性,前50名重合率达98%,而与主成分分析综合评价的重合率仅有6%,说明使用TOPSIS等传统评价模型对候选学校绩效指标值进行排名更合适。     

The Prospect for O.R. in the Nigerian Government Service—An Administrators' Viewpoint

The paper reports the results of interviews with senior government administrators in Nigeria in which they were asked a range of questions about their own work and about the problems that are likely to be encountered in trying to introduce operational research into the government service. It is thus in contrast with most papers on O.R. in developing countries, which are written primarily from the viewpoint of practitioners. The administrators confirmed that there was a wide range of problems recognized as being suitable for the O.R. approach, and identified some of the barriers to the introduction of an effective O.R. service.     

The Changing Role of O.R.

The authors set out to consider the activities of their own O.R. group at British Airways in the light of Russ Ackoff's papers delivered at the 1978 ORS Conference, but the paper has developed into a discussion of Ackoff's ideas from the viewpoint of an in-house industrial O.R. group that has had considerable success in implementation and has thought a great deal about what it is trying to do. Particularly relevant is the emphasis placed by this O.R. group on highly interactive planning models and systems and on an evolutionary approach to development. Some attempt is made to put Ackoff's ideas into an historical perspective and his main points are discussed one by one. The authors are in sympathy with the direction Ackoff is pressing, but not with the gloom his paper has generated in some quarters.     

Orthogonal rotation in PCAMIX

Kiers (Psychometrika 56:197–212, 1991) considered the orthogonal rotation in PCAMIX, a principal component method for a mixture of qualitative and quantitative variables. PCAMIX includes the ordinary principal component analysis and multiple correspondence analysis (MCA) as special cases. In this paper, we give a new presentation of PCAMIX where the principal components and the squared loadings are obtained from a Singular Value Decomposition. The loadings of the quantitative variables and the principal coordinates of the categories of the qualitative variables are also obtained directly. In this context, we propose a computationally efficient procedure for varimax rotation in PCAMIX and a direct solution for the optimal angle of rotation. A simulation study shows the good computational behavior of the proposed algorithm. An application on a real data set illustrates the interest of using rotation in MCA. All source codes are available in the R package “PCAmixdata”.     

Personal Computers and Operational Research — Experience in British Steel

The exploitation in personal computers of the well-publicized micro-technology is seen by the author as a major development with significant implications for O.R. This paper considers the nature of the implications from the point of view of the central O.R. unit of the British Steel Corporation and discusses that unit's response. The personal computer options are discussed and the applications policy which has been evolved for the author's department explained.     

Operational Research for the Real World: big questions from a small island

The address explores three questions that are important for operational research: ‘Where do we come from?’, ‘What are we?’ and ‘Where are we going?’ First, it looks briefly at the history of O.R. from Babbage to Blackett and the importance of a ‘union of theory and practice’ in our work. Then it looks at O.R.'s identity and image and argues that we do have a reasonably clear idea of our identity, although we do not give sufficient prominence to our contribution to improving system design. It also argues that the ‘brand image’ of O.R. has become diluted and needs to be simple, distinctive, relevant and compelling. In considering how we might achieve that, by addressing the third question, it proposes that we should grow our capability and activity in accommodating ‘analytics’, in building in behavioural science, in coping with complex systems, in developing design thinking and in encouraging evaluation. It also suggests strengthening bridges between academics and practitioners, between those working in different specialisms and in diverse sectors and between O.R. and the public. Finally, it argues that such developments would assist O.R. to reinforce our bridge between science and the humanities and enable us to better meet the challenges of the ‘real world’.     

The municipal financial planning model: A simultaneous regression equations and goal programming approach

Most of today's city managers are concerned about municipal financial problems. In trying to resolve these problems, scientific planning tools are needed to examine the optimality of resource allocation. For the municipal financial policy planners, the following two points are important.

• 1.(1) Statistical aspects. Since there are many economic variables in municipal financial problems, it is necessary to clarify the relationship among these variables and to infer the parameters through a statistical approach.
• 2.(2) Mathematical aspects. Policy-planners must specify the optimal value of these variables so as to attain the multiple goals of a local government.

Econometric models, especially the simultaneous equations approach, are appropriate for statistical analysis; whereas a goal-programming formulation may be used for mathematical aspects of the problem.In this paper, we propose and show that these two models can be combined. We call this the GPE model.The GPE model is applied to Urawa City. The Urawa model is composed of 6 structural equations 9 variables and 4 scenarios from the standpoint of future insight of Urawa City.From the Urawa Case, we conclude that the GPE model may be a practical tool for the municipal financial planning of other local governments.     

Organisational linkages and O.R. projects

An empirical study of a group of O.R. projects in presented with particular attention being paid to organisational interactions. The results are derived from detailed investigations of O.R. projects in which both the managers(s) and O.R. practitioner(s) were interviewed. This initial exploration has indicated a variety of organisational forms, and revealed the importance of non-formal processes that often take place.     

Micro,Mini or Mainframe—What's Right for You?

An investigation was undertaken in late 1982/early 1983 into the computing needs of operational research workers in British Gas. The approach was first to draw up a specification of O.R.'s computing needs in terms of service levels, provision of hardware and software. Alternative options for meeting this specification were then costed out. Options examined included an interactive service on the mainframe computer, use of a minicomputer, and the use of micros plus mainframe interactive service. The results are given in the paper for various sizes of O.R. group, together with the results of sensitivity exercises.     

The Organization and Improvement of Market Forecasting

Quantitative forecasting techniques are not much used in organizations. Instead, organizations rely on the judgement of managers working close to the product market. Increasingly however, developments at the interface between marketing and operations require more accurate forecasting. Quantitative marketing models have that potential. Drawing on theories from the ‘diffusion of innovation’ literature and results on ‘the barriers to effective implementation’, this paper first considers those factors that should be included in any complete evaluation of market forecasting. Using this framework and based on detailed survey work in a multi-divisional organization, the paper then describes how this company produces its market forecasts, and the perceptions of its managers as to inadequacies in the procedures. Reasons are proposed as to why quantitative forecasting techniques are not effectively used. The paper concludes with a discussion of the causes behind the organization's mismanagement of their forecasting activity and how these activities might best be improved.     

A Materialist Analysis of Operational Research

Accounts of the development and practice of operational research have commonly stressed its timeless universality as a method for rational decision-making. In this paper operational research is seen as one element in the managerial response to problems of complexity and uncertainty within an economic system characterised by institutionalised conflict. Both the material and ideological functions of ‘management science’ in private and public enterprise are analysed, and characteristics are identified of an emergent ‘workers science’. Editor's Note The title of this paper contrasts the materialistic approach with the idealistic approach, and the content of the paper disowns the latter. Evidently there are alternative but overtly political terms for both adjectives.It would be stupid if O.R. were to ignore the political facts of life which play so great a part in the decisions and policies with which O.R. is concerned. But, as the authors acknowledge, other interpretations of history than those presented here are at least possible.Contributions offering alternative schemata, or based on other paradigms, are invited and will be given careful consideration.     

A new implementation of Yen’s ranking loopless paths algorithm

Yens algorithm is a classical algorithm for ranking the K shortest loopless paths between a pair of nodes in a network. In this paper an implementation of Yens algorithm is presented. Both the original algorithm and this implementation present computational complexity order when considering a worst-case analysis. However, computational experiments are reported, which allow to conclude that in practice this new implementation outperforms two other, Perkos implementation and a straightforward one.AMS classification: 05C38, 05C85, 68R10, 90C27.Ernesto Q.V. Martins: Sadly, the author passed away in November, 2000.Marta M.B. Pascoal: The research of Marta Pascoal was developed within CISUC and partially supported by the Portuguese Ministry of Science and Technology (MCT), under PRAXIS XXI Project of JNICT.     

Validation of decision-aiding spreadsheets: the influence of contingency factors

This paper describes an investigation into the influence of contingency factors on the validation of spreadsheet-based decision support systems (DSS), and develops a methodological framework for validation that takes account of the effect of contingency factors. The research extends and confirms previous research by one of the authors who identified relevant contingency factors. The perceived influence of these contingency factors on validation effort was investigated by an empirical study, and the results of this study were then used to derive contingency-related guidance for validation. This was evaluated by a sample of practitioners and academics with experience in the development of spreadsheet-based DSS, and was then incorporated into a methodological framework for validation. The framework is designed to enable managers, decision-makers, project leaders and other non-OR specialists to identify the extent of validation effort likely to be required to ensure that the spreadsheet models that they build are valid. The research has implications for the validation of other types of OR models.