摘要:

AbstractThe paper addresses one aspect of the rostering problem posed to the public transport company operating in Porto, Portugal. The specific problem dealt with in this paper is that of sequencing the duties within each rota (rotating schedule) so as to minimize the variance of the rest periods between successive duties while satisfying constraints on their minimum value. This problem is formulated as a travelling salesman problem. Solutions derived from two heuristics are compared with the optimal ones.

ISSN:0160-5682    

DOI:10.1057/jors.1995.61

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

AbstractThis paper considers the use of alternative methodologies for assessing corporate performance of industrial sectors within the economy. It is argued that the use of ratio analysis in itself is insufficient for assessing performance, and that more advanced tools like data envelopment analysis should be used to complement ratio analysis. Data envelopment analysis is used in the paper to address a series of issues concerning the measurement of corporate performance, which includes an assessment of sales' efficiency, the effects of economies of scale, benchmarking of a firm's performance and the association between industry groups and performance. The paper uses data drawn from the grocery industry in the UK.

ISSN:0160-5682    

DOI:10.1057/jors.1995.62

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

AbstractIn this paper we consider the problem of determining teaching and research efficiencies for university departments concerned with the same discipline. Considering this problem highlights the issue of how to determine efficiencies when resources are shared between different activities, and a non-linear approach to this issue based upon data envelopment analysis is presented. Computational results are given for chemistry and physics departments in the United Kingdom.

ISSN:0160-5682    

DOI:10.1057/jors.1995.63

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

AbstractThis paper describes an approach taken to carrying out multidisciplinary action research into contract management within the National Health Service. The work forms part of the‘Contracts and Competition Programme’funded by the Economic and Social Research Council. The members of the team had little experience of multidisciplinary research prior to the start of the study and little guidance in this regard is provided in the management science literature. Hence, there was a clearly identified need to develop an approach capable of guiding the work and ensuring that the wide range of disciplinary perspectives within the team could be successfully incorporated into an integrated whole. The approach taken makes use of concepts from soft systems methodology to provide an overarching framework for this purpose and this paper reports on its successes and failures.

ISSN:0160-5682    

DOI:10.1057/jors.1995.64

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

AbstractThe multi-item lot-sizing problem considered here is concerned with finding the lot sizes over a horizon of discrete time periods to meet known future demand without incurring backlogs, such that the total cost of production and inventory holding is minimized. The capacity constraints arise because the production of each item consumes capacitated production resources at a given rate. Production is assumed to occur without set-ups. The problem is formulated as a capacitated trans-shipment problem. Use of modern, minimum-cost network flow algorithms, coupled with appropriate starting procedures, allows realistically large problem instances to be solved efficiently; thus obviating the need for specialized algorithms based on restrictive assumptions regarding cost structures.

ISSN:0160-5682    

DOI:10.1057/jors.1995.65

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

AbstractData Envelopment Analysis (DEA) is an approach to assess the relative efficiency of organizations using multiple inputs to produce multiple outputs. This assessment is made from the standpoint most favourable to each organization. If an organization is not well enveloped, in the sense that it is not comparable to a sufficient number of other organizations (called referents), DEA may understate inefficiency. A lower bound on the efficiency measure may be obtained by requiring that the organization being evaluated be compared with at leastknon-redundant referents. For any feasible choice ofk, the procedure proposed here selects the most favourable set of referents, and guarantees a greatest lower bound on the efficiency measure, thus usefully complementing the information provided by conventional DEA.

ISSN:0160-5682    

DOI:10.1057/jors.1995.66

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

AbstractThis paper discusses a method of comparing different prioritization techniques that entails mapping the input data from one system to another. The ranking vectors output by the methods should then be comparable. As an illustration, a method that uses pairwise comparison, e.g. the Analytic Hierarchy Process (AHP) of Saaty, itself viewed as a mapping, is compared with a method using cross impact analysis, the Edinburgh Approach. The problem centres on an appropriate inverse of the process mapping. Although the discussion is restricted to simple bilevel hierarchies, useful insight is provided into the methodologies in general and, in particular, the problem of inverse inconsistency associated with rank reversals. A way in which the theory of AHP might be incorporated into a Differential Hierarchy Process is suggested.

ISSN:0160-5682    

DOI:10.1057/jors.1995.67

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

AbstractWe consider the problem of obtaining integer solutions to a minmax linear programming problem. Although this general problem is NP-complete, it is shown that a restricted version of this problem can be solved in polynomial time. For this restricted class of problems two polynomial time algorithms are suggested, one of which is strongly polynomial whenever its continuous analogue and an associated linear programming problem can be solved by a strongly polynomial algorithm. Our algorithms can also be used to obtain integer solutions for the minmax transportation problem with an inequality budget constraint. The equality constrained version of this problem is shown to be NP-complete. We also provide some new insights into the solution procedures for the continuous minmax linear programming problem.

ISSN:0160-5682    

DOI:10.1057/jors.1995.68

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

AbstractAlthough attempts have been made in the past to modify the economic order quantity (EOQ) model to the maximization of return on investment (ROI), they either failed to take the whole enterprise into account, or reached the erroneous conclusion that no adaptation is required for that purpose. In this paper we develop the company-wide ROI maximizing order quantity, and show that it is bounded from above by EOQ and that it does not necessarily follow the square root of the demand level. In fact, there are conditions under which the order quantity is constant, regardless of the demand level, or even decreasing with demand. It is important to note that such a policy, if undertaken by many firms, will reduce the economic accelerator, and thus reduce the volatility of business cycles.

ISSN:0160-5682    

DOI:10.1057/jors.1995.69

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

AbstractThe problem of locatingpmaximally dispersed points in a convex space is considered. This problem is formulated as a non-linear programming problem. It is shown that this problem, in a square, is equivalent to the problem of packing the square withpequal circles of largest possible radius. Computational experience with the non-linear programming formulation of the dispersion problem is reported. Four of the solutions found are superior to the best known solutions in the literature for the corresponding circle-packing problem.

ISSN:0160-5682    

DOI:10.1057/jors.1995.70

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor