摘要:

AbstractCognitive style refers to differences that can be perceived in individuals due to differing cognitive structures. There has been a large amount of research on how cognitive style affects managerial decision-making, particularly in the context of management information systems, but little or no attempt to relate these findings to operational research. This paper reviews the findings of cognitive-style research from the perspective of operational research, and draws a number of useful inferences concerning the matching of OR aids to managers, the presentation of information and recommendations, the use and acceptance of OR, and the structure of OR groups. Further, it is argued that cognitive-style findings help to give a justification to the move towards‘soft’approaches to analysis.

ISSN:0160-5682    

DOI:10.1057/jors.1989.68

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractIn this paper an integer, non-linear mathematical programming model is developed to allocate emergency medical service (EMS) ambulances to sectors within a county in order to meet a government-mandated response-time criterion. However, in addition to the response-time criterion, the model also reflects criteria for budget and work-load, and, since ambulance response is best described within the context of a queueing system, several of the model system constraints are based on queueing formulations adapted to a mathematical programming format. The model is developed and demonstrated within the context of an example of a county encompassing rural, urban and mixed sectors which exhibit different demand and geographic characteristics. The example model is solved using an integer, non-linear goal-programming technique. The solution results provide ambulance allocations to sectors within the county, the probability of an ambulance exceeding a prespecified response time, and the utilization factor for ambulances per sector.

ISSN:0160-5682    

DOI:10.1057/jors.1989.69

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractSelecting an appropriate simulation-model structure for complicated, large-scale transport systems is a non-trivial and challenging task. This paper reports practical research which evaluates a number of alternative model structures for the Arizona state-highway network system based on the immediate dependency on input data obtained from a multistage mail survey. The most appropriate topology structure selected is a data-driven, link-based, discrete-event simulation model using conditional probability branching logic. Separating model and data makes the simulation model a generic traffic-routeing logic processor that is easy to use and does not require simulation skills. Different transport systems can easily be accommodated by simply changing input data. The model is validated by comparative analysis of input data using statistical techniques. An upper bound on the size of the valid network is thus obtained.

ISSN:0160-5682    

DOI:10.1057/jors.1989.70

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractA method is proposed for the allocation of units of blood from a regional blood transfusion centre to the hospitals of its area, taking into consideration the characteristics of the individual hospitals, such as the transfusion activity, the demand of each hospital and the regional blood transfusion service policy concerning the allocation of units of blood expressed through a utility function. The problem is formulated as a stochastic programming problem but reduces to a linear programming problem and therefore is easily applicable. The method is suitable for application in systems with a National Health Service system, such as the British. Finally the results are given of an application to the despatches of units of blood in the Regional Blood Transfusion Service of Glasgow and West of Scotland.

ISSN:0160-5682    

DOI:10.1057/jors.1989.71

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractThis paper examines EOQ under date-terms supplier credit, making explicit the separate effects on inventory policy of the two components of carrying cost-namely, financing cost and other variable holding costs. When a distinction between these types of holding costs is made, EOQ can no longer be expressed as a simple formula. Rather, optimal order quantity must be determined by search over a well-defined range of order quantities which encompasses the classical EOQ. The conclusion currently contained in the literature that the optimal order quantity under date terms is always given by an integer multiple of monthly demands no longer applies. In particular, a unique feature of date-terms credit is the possible existence of multiple EOQs.

ISSN:0160-5682    

DOI:10.1057/jors.1989.72

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractA new mathematical model for the multi-travelling salesman problem (MTSP) is presented. The MTSP formulation is modified, and a branch-and-bound algorithm for solving this problem exactly is developed. The significance of this procedure is that it does not need to transform the problem into a single travelling salesman problem, which has been the case in the dominant algorithms for solving the above problem. Moreover, computational experience has shown that for a fixed number of cities to be visited, the time required to solve the problem decreases markedly as the number of salesmen increases.

ISSN:0160-5682    

DOI:10.1057/jors.1989.73

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractDynamic location-routeing problems involve the determination of the least-cost sequence of depot, vehicle fleet and route configurations in a distribution system, over a given planning horizon. This paper presents two solution approaches to such problems. The first is an exact method which is appropriate for small-scale problems. It consists of representing the problem by a suitable network and of solving to optimality an integer linear programme associated with the network. In the second approach, some of the system costs are approximated, and a global solution is then obtained by determining a shortest path on a directed graph. Under some hypotheses, this approach is suitable for large-scale problems. It is illustrated on a simple example.

ISSN:0160-5682    

DOI:10.1057/jors.1989.74

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractAn order-level inventory model is developed for deteriorating items with uniform rate of production and stock-dependent demand. Shortages are allowed, and excess demand is backlogged. Results are illustrated with numerical examples.

ISSN:0160-5682    

DOI:10.1057/jors.1989.75

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractConsider an organization with several categories of staff, each having a specified number of members. The age of entry into service and the age of retirement are both specified. Withdrawals occur at time-independent rates. Under this set-up, the authors have computed the maximum ages at which promotions should take place, assuming that the staff members continuing at various ages are random. Some illustrative calculations have been carried out.

ISSN:0160-5682    

DOI:10.1057/jors.1989.76

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractThis paper presents the discounted cash-flows (DCF) approach for the analysis of the optimal inventory policy in the presence of the trade credit. The DCF approach permits a proper recognition of the financial implication of the opportunity cost and out-of-pocket costs in inventory analysis. This approach also permits an explicit recognition of the exact timing of cash flows associated with an inventory system. As a result, the effect of the delayed payment is appropriately reflected in determining the optimal order size.

ISSN:0160-5682    

DOI:10.1057/jors.1989.77

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor