Showing papers in "Omega-international Journal of Management Science in 1985"

Weighted similarity measure heuristics for the group technology machine clustering problem

Abstract: Heuristique de mesure de similitudes ponderees appliquee au probleme du groupement des machines en cellules dans la technologie de groupe

The facets of group technology and their impacts on implementation—A state-of-the-art survey

Abstract: The recent use of the Group Technology concept of grouping parts into ‘families’ has received much notice due to the integration of this technique with the varied technologies of computer integrated manufacturing. This is but one of the facets of Group Technology, which is essentially a set of techniques and operating policies designed to improve the operational efficiency of manufacturing. With the exception of the parts grouping concept, the many facets of Group Technology have been largely neglected. This paper presents a survey of the literature on the concepts of Group Technology, attempts to categorize these topics in a natural manner, and link the processes, technology and experiences together. This paper reviews the problems addressed and the optimal and heuristic solution methodologies suggested in the literature. The conclusion indicate various areas and topics for future research/implementation activities.

A categorized bibliographic survey of goal programming

Abstract: A total of 240 goal programming articles that have so far appeared in over 60 English journal publications are compiled and classified according to technique and application areas. Analysis of these data provides interesting insights regarding goal programming article characteristics, literature trends and future needs.

Trim loss and related problems

Abstract: Because of the diversity of the structures of real-world trim loss (or cutting stock) problems there exist no general standard methods for solving these problems. Hence many solution methods for trim loss problems have been developed in practice, especially heuristics. Since these methods are strongly based on the particular problems to which they are applied, the study of papers on problems with a comparable structure may prove helpful. In this paper a detailed catalogue of criteria for characterization of real-world trim loss problems is developed in a differentiated and systematic manner. The main criteria are: dimension, planning situation, goal, restrictions and solution approach. The proposed system of classification is based on 34 case studies found in the relevant literature. The classification of these case studies is represented by means of a ‘classification schedule’. In view of existing formal similarities the classification system can also be of importance for (bin) packing and loading as well as some assortment problems.

Developing expert systems for management applications

Abstract: The Alvey Report has resulted in a growing interest in the UK in ‘expert systems’. It is fairly generally accepted, at least in the UK, that such systems function in a particular type of way, i.e. they arrive at decisions through a process of rule based inference. It is suggested that it may be more fruitful to regard rule based inference as one approach to the construction of expert systems, and that proven techniques of operational research may well be more useful in constructing other types of expert system. Alternative applications of expert systems are derived on the basis of a broader definition of an expert system in terms of what it does rather than how it does it. A parallel is drawn between these applications and some typical concerns of business research. It is suggested that a useful aid in identifying promising business applications of expert systems is to set up four ‘dimensions’ along which different types of system differ. Examples are given of where other techniques might conceivably be useful in applications of expert systems.

A heuristic for facilities layout planning

Abstract: A new matrix representation of a planar graph and its dual is presented. This is then used to implement a heuristic for facilities layout planning.

The maximum and sum of two beta variables and the analysis of PERT networks

Abstract: This paper explores the errors involved in the approximation of both the maximum and sum of two independent Beta random variables, each by another Beta random variable. The principal area of application is the time analysis of PERT networks, and the results are interpreted and discussed in terms of this application. The error was found to be acceptable for the greater part of the range of the parameters involved. The results will help practitioners estimate the mean and standard deviation of the completion time of PERT networks.

Teaching operations research on microcomputers

Abstract: Teaching operations research on microcomputers is just beginning. The first educational packages (diskettes plus guides) recently appeared (1983) on the market, and many faculty members and trainers in industry are wondering how to evaluate and use these or industry packages in an efficient and effective manner. This paper examines this issue from different aspects: experience in the classroom, software availability, criteria for selecting classroom software, and microcomputer hardware.

Systems analysts and the politics of organizational control

Abstract: The introduction of major information systems into organizations can be fraught with difficulties. The negative effects of such systems can, for many important organizational members, be too great a price to pay for the supposed benefits. The advent of computerised information systems has served not merely to deskill the clerical ‘craft’ but can also be used as a strategy by top management to reduce the management control gap. However, by undercutting the organizational ‘rules of the game’, information systems innovation can produce severe strains and stresses in the political system. The proposals in the literature to combat the effects of innovation are examined. A broader, political perspective is used to reveal some of the inadequacies of these proposals and supporting data, gathered from interviews in several Canadian organizations, are presented to illustrate this. The paper ends with a discussion of the implications of this broader approach.

Testing of the «reduction of compound alternatives» principle

Abstract: This paper reports an empirical investigation of the effects of three pictorial forms of problem representation on conformance with the Reduction of Compound Alternatives Principle of expected utility theory. The most common form of representation, written problem statements, was compared with three pictorial representations: tubes containing one hundred labeled balls, decision matrices with each column proportional in size to the probability of the corresponding event, and bar graphs. The tubes representation led to fewer violations of the Principle. In addition, when subjects were trained to construct proportional matrices from written problem statements, they exhibited fewer violations than those who received the same problems already formatted in proportional matrices. The results reported here should contribute to the development of a theory of the way people frame decision problems.

Managing the introduction of new technology

Abstract: Most of the existing literature on the implications of new technology focuses on either its ‘impact’ or the social choices that lie behind strategies for its introduction into work organisations. The problems of managing the implementation of new technology have yet to be extensively examined despite this being one of the most critical aspects in the process of technological change. The findings from two case studies are presented which show how managers in the organisations concerned developed contrasting approaches to the problem of implementation in the context of opportunities and constraints presented by product markets and technological advance. Similarities between the two approaches are identified, in particular the role played by top management support in facilitating the acceptance of the new technology. The argument that management is able to develop a single unitary strategy towards the introduction of new technology is rejected in favour of a view of managerial actions as a series of flexible and changing sub-strategies associated with different stages in the process of change.

Financial reporting and changing prices—A review of the issues

Abstract: The problem of accounting for changing prices, which has been discussed in the academic literature for over 50 years, has affected a wider population in the last decade as regulatory bodies in both the UK and US have developed standards requiring companies to report the effects of changing prices in their accounts. The issues raised illustrate the difficulty of defining and measuring income. Some affected by these developments argue that any price level adjustments are too subjective and wish to adhere to traditional historical cost accounting. Others who accept the case for reform cannot agree on whether allowance should be made for general price changes, specific price changes or both. Agreement cannot be reached either on the benchmark for measuring profit—whether it should be a financial or a physical one—or on the appropriate basis of valuation for the assets of a company. These issues are examined in the light of assumed user needs, showing the effects of some alternatives on profit. The requirements of the UK and US standards, and of a new proposed UK standard, are outlined to illustrate the opinions of the standard setters on these issues; these standards, though similar in parts, differ in a number of respects, particularly over what types of price change should be reflected in accounting information—and how—and what definition of income should be used.

Expert knowledge, expert systems and commercial interests

Abstract: Experience to date in building expert systems has brought a general realization of the complexity of the effort required for producing systems capable of operating on ‘real-world’ problems. The most successful knowledge-based/expert systems built to date, e.g. DENDRAL, MYCIN, PROSPECTOR and R1 have demonstrated that a considerable investment in time and dedication on the part of systems designers and experts is required to create a fully operational system. The great majority of development projects attempting to harness this new programming technology do not extend beyond creation of a prototype system largely due to lack of necessary resources, i.e. time, money and know-how. The purpose of this paper is to discuss some of the more important issues associated with development of expert systems and to provide an overview of the commercial and industrial efforts of putting expert systems to work. This paper should be of interest to those who have gained their knowledge of expert systems from the reading of non-specialist publications and thus may have been exposed to somewhat over enthusiastic accounts of the subject.

How effective are models

Abstract: This article discusses a number of common interpretations of ‘implementation’ in the literature, and how these have been confused. Various different levels of implementation are then discussed, including the concept of model effectiveness. This is concerned with both the operational effectiveness of the model, as shown by a tangible improvement in the system modelled, and the personal effectiveness in helping users learn more about the system itself. Research is then described to explore various aspects of model usage and effectiveness. The research took place in the context of a business game used by a large number of practising managers. An unusual feature of the game was the fact that participants were offered the use of a number of models to aid their decisions. The usage of the models, and their effects, were measured objectively. Results showed that models were used extensively, and their effects were advantageous in a number of ways. The implications of this work are discussed.

Reducibility of stochastic networks

Abstract: This paper deals with the problem of reducing a stochastic network to one equivalent activity. The problem was motivated by the question of determining or approximating the probability distribution function of the duration of the longest or shortest path in a stochastic network. We define a particular reduction and use it to characterize the reducibility of such a network. The network can be reduced to one equivalent activity if the network does not have a special graph which we call the ‘interdictive graph’, or IG for short. If an IG is embedded in the network, the network is irreducible. In this case, its reduction becomes possible by duplicating some of the arcs in the irreducible network. The concept of duplicating an arc is introduced, then it is used to identify the arcs which can be duplicated. The reduction procedure is stated and illustrative examples are provided. An upper bound on the number of duplications is established.

ARARMA vs ARIMA—A study of the benefits of a new approach to forecasting

Abstract: The ARARMA methodology of time series forecasting introduced by Parzen has compared well with longer established techniques such as Box and Jenkins ARIMA models in the results of a major forecasting competition. The two main differences between these methodologies are the way data is transformed to stationarity, and the interpretation of the concept of parsimonious models. The additional benefits familiarity with the ARARMA approach can bestow on those used to the ARIMA approach are identified. Following a description and demonstration of the ARARMA methodology, a comparison of forecasting performance is made. The comparison is carried out on sets of data for which published ARIMA models are available. To ensure that the comparison is of genuine forecasting ability (rather than fitting ability), a portion of data is saved solely for forecasting performance measurement. The results indicate that there are additional benefits to be gained from the ARARMA approach. The benefits lie in the approach's tendency to avoid over differencing and in the diagnostic tools for identifying the stationary ARIMA model, rather than in the different transformation to stationarity.

Strategies for corporate and business success—A survey

Abstract: In this paper we review the literature on the strategy that a company should adopt, both at a corporate level and at an individual business level, in order to be successful. Some findings from the literature are highlighted and predictions given as to how we believe research into corporate and business strategy will develop.

Process modelling and industrial energy use in developing countries—The steel industry in India

Abstract: A process model is used to study energy use and conservation in the steel industry in India. Production is modelled by a set of inter-connected process activities, each of which defines unique relationships between process output and a number of inputs. Contrary to that in process models for the U.S., we do not assume cost minimizing behavior. Simulation results show that although a number of cost-effective energy conservation measures exist, none of them would lead to significant reductions in energy use. Effective policy for the Indian Steel industry would require combining the strategies.

Towards a theoretical clarification of the ‘spillover’ and ‘compensatory’ work/leisure hypotheses

Abstract: Two thorny problems have attracted the interest of work/leisure researchers in recent years: (1) the failure of previous research to clearly isolate the relationship between work and non-work from the effects of other confounding variables, and (2) a widespread failure to distinguish between the meanings that people attribute to work (and non-work) and the forms of work (and non-work) people perform. The argument for phenomenological research is made; in this way, empirically-grounded ‘common sense’ definitions of work and leisure could be created and these definitions could be used as a solid research base to test ‘spillover’ and ‘compensatory’ theories of the work/leisure relationship. The author then demonstrates, through the development of an analytic framework for viewing the work/leisure relationship, the fact that ‘compensatory’ and ‘spillover’ hypotheses are potential alternative modes of explanation. Unless the conditions under which each might apply can be specified, one or the other hypothesis can explain a given empirical relationship between the two variables. This further supports the need for solid phenomenological research.

An investigation of company product decision making

Abstract: This article is concerned with an investigation of the approaches taken by companies in making product decisions. The first part is concerned with a review of the range of product decisions as presented within the literature. This range is established within the context of corporate planning, with a major split between long term strategic planning product decisions, and short term operational planning product decisions. The second part of the article is concerned with the results of a survey that was designed to investigate the criteria that companies use within their product decision making. These criteria included those applicable to strategic planning, but also incorporated a range of criteria applicable to short term operational planning, as proposed in a recent article by Greenley [8]. The overall conclusion to the survey results was that a common and universal approach to product decision making cannot be identified within this sample of companies. A low level of agreement as to the relative degree of importance of the criteria was evident, and, little attention to differentiating product decisions with time was also evident. The results also challenge the importance given by the literature to the concepts of product life cycle, portfolio analysis and synergy. Finally, the author suggests two implications as a consequence of these results.

An LP model for assessing congeneration strategies

Abstract: A linear programming model is described which is designed to assist in the assessment of optimum operational strategies for industrial plants with cogeneration facilities. A concise format is provided for linking together basic elements such as boilers, valves, turbines and processes with steam and electricity demands with steam, fuel and electricity balance equations. The model should prove particularly useful for assessment when electricity tariffs have time-of-use energy or demand charges or when tariffs have conditions which require consideration of strategies over an extended period. The model has been applied to a paper mill which utilises pass-out turbines for cogeneration of electricity and process steam. Results indicate that savings in fuel costs of the order of 400,000 dollars per year could be obtained by implementing optimal strategies for operating the present turbines. Savings of the order of one million dollars per year could be obtained by converting the turbines to give high pressure pass-out steam and then operating optimally.

Multi-product batch production on a single machine. A problem revisited

Abstract: When several products are processed one at a time on a single machine, the conventional approach of computing the economic batch quantity for each product cannot apply. An example for six products is considered, where the total production capacity on regular time is inadequate, so that overtime has to be used at an extra cost. A simple method is described for solving this problem when each product is produced once during a production cycle, the objective being to minimize the total set-up and holding costs per day. Schedules which involve batch splitting can reduce these costs further, and a guideline is proposed for the construction of sub-cycles. The results compare favourably with lower bounds computed for the purpose.

A comparison of applications of microcomputers in production

Abstract: Earlier research has established that the full potential of microcomputers is not being achieved by production management in small companies. Moreover, questionnaire results and in-company interviews were used to support suggested reasons for this situation. This paper reports further work carried out to examine the issues raised in far more detail. Collaboration took place with nine separate companies over a range of applications. Three of these case studies are presented in detail, and general conclusions drawn relating both to these specific studies and to the total collaboration.

A multiple goal methodology for evaluating management information systems

Abstract: The behavior and performance of an organization are intimately tied to the mode and effectiveness of its information processing function. While there is a rapidly expanding level of research concerned with the design, development, and implementation of management information systems (MIS), relatively few approaches to the evaluation and improvement of these systems have been suggested. The current paper develops a multiple goal methodology aimed at filling this gap by evaluating and, if necessary, subsequently modifying any given set of MIS design variables considered capable of enhancing a series of operational and, perhaps, conflicting goals. The methodology is based on a series of significant findings from the MIS design literature. In particular, the procedure incorporates the tripartite of decision type/decision-maker/MIS design into the evaluation process. The methodology is user-based, being flexible with respect to the definition of performance objectives, evaluation measures, design variables, and correction strategies. A brief example applies the methodology to the evaluation of an MIS within a health services organization.

Organizational implications of CAM

Abstract: The new competitive conditions of the 1980's have thrown American and European manufacturing into a turmoil. Computerized process technology can help ease the problems through increasing productivity, quality and flexibility. However, its benefits will not be realized unless manufacturing managers attend to the technology's strategic and organizational implications. Issues in specifying the connections between computerized processes and strategic objectives are discussed. A conceptual framework is proposed which identifies some of these connections. Determining the appropriate work organization and compatible systems and procedures are also discussed. Recommendations are made for dealing with these issues.

The effect of ‘experience’ on information preferences

Abstract: A decision-maker's experience is thought to affect how he/she chooses the information that support his/her selection among alternatives. Unfortunately, results from empirical studies designed to demonstrate this hypothesis are not in agreement about the existence and/or extent of the relationship. Since one possible explanation for conflicting in results is variability in the operationalization of the variable ‘experience’, this study was designed to determine if it matters whether one chooses a macro view of experience (in which the focus is on a decision-maker's overall experience) or a micro view of experience (in which the focus is on specific experience with the decision under consideration). Additional insights regarding problems in operationalizing ‘experience’ were generated as a result of these analyses to provide a basis for further research in this area.

Determinants of Corporate Performance

Abstract: As suggested in Chapter 2, the mission statement serves as a trigger to raise many questions that need to be asked about the way in which an enterprise should be managed in order to achieve success. A key function in the management control process is monitoring the operations performed by various parts of the organization, coupled with analysis of performance at the corporate level The purpose of this control process is two-fold: First, the senior executives need to understand why the company has performed in the way that it has, and secondly, they constantly wish to explore alternative courses of action that would improve that performance.