摘要:

AbstractDespite a history of successful applications to operational-level problems, the vale of OR/MS modelling techniques as aids in policy/strategy formulation has not been widely demonstrated. In this paper, we suggest that the language of traditional OR/MS model structures is too restrictive to deal with issues typically confronted in policy-making. Differences between operational-level decision-making processes and policy/strategy formulation processes are discussed; alternative model structures are described and classified; and a modelling language for addressing issues of policy and strategy is proposed. The language is presented in set-theoretic terms, and the resulting structure implies that certain model classes accommodate policy-level management needs better than others. Furthermore, policy-level models must serve a role distinct from the prediction and optimization role typically served by operational-level models.

ISSN:0160-5682    

DOI:10.1057/jors.1979.69

出版商:Taylor&Francis    

年代:1979

数据来源: Taylor

摘要:

AbstractThe Torres Strait, situated between Australia and New Guinea, is a major shipping route to east Australian ports. This paper describes a tidal window technique which assists deep draught vessels to plan their passage through the strait and allows analysis of regulations relating to keel clearance.

ISSN:0160-5682    

DOI:10.1057/jors.1979.70

出版商:Taylor&Francis    

年代:1979

数据来源: Taylor

摘要:

AbstractA practical study is described where the normal stock control assumption that lead times are constant is not valid. Assuming lead time variability two methods of generating buffer or minimum levels are described, a method of numerical generation and analytical generation. Numerical generation is rejected on practical ground which may have a wider applicability. In calculating the Economic Order Quantity (E.O.Q.) a novel approach is used in which the difficulty in obtaining the cost of ordering and stock holding is overcome by taking the work load on the purchasing department (and hence the number of orders placed) as of prime importance.

ISSN:0160-5682    

DOI:10.1057/jors.1979.71

出版商:Taylor&Francis    

年代:1979

数据来源: Taylor

摘要:

AbstractThis paper describes a method for maximising payloads carried by a fleet of road tankers. The tankers carry a range of products in multicompartment tanks. A case study demonstrates the method's potential to increase payload and remove the risk of overload penalties.

ISSN:0160-5682    

DOI:10.1057/jors.1979.72

出版商:Taylor&Francis    

年代:1979

数据来源: Taylor

摘要:

AbstractSome£400m was estimated as having been staked on gaming machines ("fruit" machines or one-armed bandits) in Great Britain during 1976, making them the form of gambling with the third highest turnover after casinos and off-course betting. Yet little work has been done on their properties, particularly of modern sophisticated machines which incorporate so-called "features" such as "HOLD", "GAMBLE" and "NUDGE" designed to make them more interesting as a gambling medium. The difficulties involved in assessing the properties of such machines, particularly those resulting from the inclusion of a "HOLD" mechanism, are discussed. The basic random variables needed to describe their behaviour are defined; the consequent problems of determining the "expected pay-out" of a machine, both for the purposes of describing its properties to players and for testing the performance of the machine, are investigated. This work is placed in the context of the recommendations of the recent report of the Royal Commission on Gambling.

ISSN:0160-5682    

DOI:10.1057/jors.1979.73

出版商:Taylor&Francis    

年代:1979

数据来源: Taylor

摘要:

AbstractA Markov chain model for the description, testing and comparison of wastage in hierarchical manpower systems is given in this paper. With regard to manpower planning, emphasis is placed on unnatural wastage (resignations, dismissals and transfers) in comparing systems. All forces of transition are state and service length specific. The model is tested on data from the Danish State Police Force and a combined group of English Forces for the period 1968-72.

ISSN:0160-5682    

DOI:10.1057/jors.1979.74

出版商:Taylor&Francis    

年代:1979

数据来源: Taylor

摘要:

AbstractAn Order-Level inventory model continuous in units and discrete in time is developed for deteriorating items. The model is developed under deterministic demand and instantaneous delivery. Deterioration is assumed to be a constant fraction of the onhand inventory. An example is given to illustrate the model.

ISSN:0160-5682    

DOI:10.1057/jors.1979.75

出版商:Taylor&Francis    

年代:1979

数据来源: Taylor

摘要:

AbstractAn integrated production inventory model is considered in this paper, for a flow shop type multiproduct batch production system, with a multifacility structure. Instantaneous production is allowed in each facility. The model aims to determine simultaneously the optimal manufacturing cycle for the multiple products and the corresponding optimal procurement policies for the raw material. The cycle concept of multiproduct batch processing is extended to multifacility system and is integrated with the concept of production-inventory system for a single product, single facility system.

ISSN:0160-5682    

DOI:10.1057/jors.1979.76

出版商:Taylor&Francis    

年代:1979

数据来源: Taylor

摘要:

AbstractThe Hamiltonian Path problem is a variant of the travelling salesman problem, in which the tour is not a closed curve. It has been demonstrated that the optimal path through all the points in some finite subset of Euclidian two space must take the vertices of each "half" of the convex hull in the order prescribed by the convex hull. This fact is used to develop two heuristics. These are tested against problems for which the optimal solution is determined by other methods. These comparisons as well as measures of computational efficiency are presented.

ISSN:0160-5682    

DOI:10.1057/jors.1979.77

出版商:Taylor&Francis    

年代:1979

数据来源: Taylor

摘要:

AbstractThis paper presents an efficient solution algorithm for the multiconstraint zero-one knapsack problem through a branch and bound search process. The algorithm has been coded in FORTRAN; and a group of thirty 5-constraint knapsack problems with 30-90 variables were run on IBM 360/75 using two other codes as well, in order to compare the computational efficiency of the proposed method with that of the original Balas and an improved Balas additive algorithms. The computational results show that the proposed method is markedly faster with regard to the total as well as the individual solution times for these test problems, and such superiority becomes more evident as the number of variables and the difficulty of the problems increase. The results also indicated that the original Balas method is extremely inefficient for the type of problems being considered here. The total solution time for the thirty problems is 13 min for the proposed method, 109 min for the improved Balas algorithm, and over 380 min for the original Balas algorithm. Extension of the solution algorithm to the generalized knapsack problem is also suggested.

ISSN:0160-5682    

DOI:10.1057/jors.1979.78

出版商:Taylor&Francis    

年代:1979

数据来源: Taylor