摘要:

AbstractThe planning of services within district health authorities is a complex task, but the process of planning is often crude: few options for addressing issues are considered, and these are inadequately assessed. These deficiencies led to research of which the aim was to identify the types of information and systems needed for improved planning. This paper describes the product of that research, the Hospital Planning Model. It is a decision-support system which gives planners fast access to relevant information for planning hospital services. This allows them to consider quickly a range of options for addressing a particular planning issue, and to test how sensitive the implications of proposals are to differing planning assumptions. The system has been shown to be generalizable, and is currently used in 28 health districts and other health organizations throughout the United Kingdom. The proposed reforms of the NHS are likely to increase the relevance of the system: the purchaser/provider market will result in a greater awareness by hospitals of the importance of identifying measures to improve the cost-effectiveness of care. Purchasers too may want to scrutinize hospitals in terms of their efficiency.

ISSN:0160-5682    

DOI:10.1057/jors.1990.158

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractUsing an observational study of the operation of a cement kiln and a set of operational rules published by Peray and Waddell, five knowledge-based advisory systems have been developed encapsulating the supervisory expertise of the process operators. The advisory systems were developed in the logic language PROLOG. Each expert adviser was applied to a set of plant data previously logged from the kiln, and the advice offered was compared with the actions taken by the operators. Statistical tests have been applied to the outcome of the comparisons in order to determine which expert adviser emulated the operator performance most successfully. The results demonstrate the value of such tests in quantitatively validating expert systems. In addition, the supervisory techniques that the operators were using in practice were identified.

ISSN:0160-5682    

DOI:10.1057/jors.1990.159

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractThis paper deals with the problem of two-level production control with disturbances. A production system is considered with several machines on the lower level and a section on the upper one. Each machine produces a given target amount by a given due date (common to all machines). Each machine has several possible speeds, which are subject to disturbances. On the machine level, at the routine control point, decision-making centres on introducing the proper speed and determining the next control point. It is assumed that all the target amounts are transferable; i.e. a part of each target amount can be processed by any other machine. In a case when it is realized, for a certain machine, that the target cannot be completed on time, the section reschedules the remaining target amounts among the machines. New target amounts are determined for the machines so that the overall target can be accomplished on time. A stochastic optimization formulation is presented, followed by a heuristic solution and simulation results.

ISSN:0160-5682    

DOI:10.1057/jors.1990.160

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractIn this paper, a multistage, single-product serial batch-production system is considered in which the demand is deterministic and cost factors, viz. inventory carrying, ordering, set-up, etc., are known. The objective is to minimize the total variable cost. A model is suggested which combines the purchasing policy of the raw materials and the production policy of the finished product. An experimental procedure is carried out to compare the model against a benchmark providing a lower bound for the total variable costs. The model is also compared with an instantaneous production-rate case. The results suggest that the model offers an interesting scope for heuristic procedures. The possible application domain of the model is also discussed.

ISSN:0160-5682    

DOI:10.1057/jors.1990.161

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractThe purpose of this paper is to develop a hybrid and practical man-machine interactive approach to solving linear programmes involving more than one objective function. The approach incorporates all the strengths and avoids the weaknesses of some existing methods. It uses the solution of a two-person zero-sum game with mixed strategies to generate efficient solutions, and then proceeds to modify the feasible region using responses from the decision-maker. The cycle is repeated until a satisfactory solution is found. An example from the literature is solved using the proposed method in order to demonstrate its applicability. A microcomputer implementation of the method is described, with illustrations from actual screen displays. A comparison of the proposed method with 14 other existing methods is also presented.

ISSN:0160-5682    

DOI:10.1057/jors.1990.162

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractWe consider a task being performed in an environment in which the work-rate (or efficiency of the processor varies with time in a deterministic manner. Given the probability density function (p.d.f.) of the total work-content of the task (i.e. processing time at 100% efficiency), we develop a closed-form expression for the p.d.f. of the task-processing time. Numerical examples are given.

ISSN:0160-5682    

DOI:10.1057/jors.1990.163

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractMany managers appear to have a mental model of how investment decisions should be carried out. This paper attempts to identify some of the characteristics of such a mental model by constructing an optimal control model of the process of authorizing an investment project. The key activities in the model are design, support generation and authorization. It is assumed that the effort that can be expended on each is limited. The objective function is the net present value of the cash flows associated with the project. The solution to the model is readily interpreted qualitatively. For viable projects, four different patterns of decision-making are found, each of which is optimum under appropriate circumstances. It is argued that in many actual investment decisions it should be possible for managers to approximate reasonably closely the optimal behaviour, and that therefore the optimal control model may shed light on managers' mental model.

ISSN:0160-5682    

DOI:10.1057/jors.1990.164

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractWe consider the static single-facility scheduling problem where the processing times of jobs are a nondecreasing and differentiable function of their starting (waiting) times and the objective is to minimize the total elapsed time (makespan) in which all jobs complete their processing. We give a criterion for optimality of two jobs to be scheduled next to each other, and based on this criterion we propose a heuristic algorithm to solve the problem. The effectiveness of the algorithm is empirically evaluated for quadratic and exponential cost functions. In the quadratic case it is compared with the static heuristic algorithm proposed by Gupta and Gupta.

ISSN:0160-5682    

DOI:10.1057/jors.1990.165

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractIn this note we present a system (OR-Library) that distributes test problems by electronic mail (e-mail). This system currently has available test problems drawn from a number of different areas of operational research.

ISSN:0160-5682    

DOI:10.1057/jors.1990.166

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractSome comments are made on the analytic hierarchy process of Thomas L. Saaty, which has gained widespread acceptance as a valuable tool for multicriteria decision-making. Saaty's validation of the method against physical laws is criticized, a multiplicative scale is suggested for making judgements, and the problem of rank reversal is discussed with reference to two published papers.

ISSN:0160-5682    

DOI:10.1057/jors.1990.167

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor