A simulation study of the operations of a telephone bureau

This paper presents a priority queueing situation: a telephone bureau which has to deal with two distinct classes of caller. The first group are making urgent calls which must be dealt with as soon as possible, while the second group are making a variety of different types of routine enquiry which are not considered to be as important. Management are concerned with a number of issues associated with the operations of their bureau, these include the levels of service offered to the different groups of caller, the effects of different levels of staffing, and the effects of changing the mix of call types. The use of applied probability theory to analyse this situation is briefly discussed, and then simulation proposed as a means to analyse the operations of the bureau. The development of this simulation is outlined, some typical results presented and its usefulness discussed.     

The application of microcomputers in production management

The findings reported result from a questionnaire survey, and a number of company interviews. Further questions which need to be answered are identified, and a research project to provide these answers is outlined.     

The use of formal inventory control models: A preliminary survey

Of the many papers and texts on the subject of inventory control, relatively few report the successful implementation of systems based on formal mathematical models developed with specific objectives in mind. This could be considered rather strange in the light of the relatively high number of papers reporting the development of models for dealing with a multitude of different hypothetical situations, and the widespread availability of computer systems capable of exploiting such models. Various reasons for this anomaly can be put forward. This paper reports the results of a preliminary survey designed to investigate this more deeply, and draws some necessarily tentative conclusions relating to factors contributing to the successful application of such systems.     

A comparison of applications of microcomputers in production

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.     

Probabilistic cost-effectiveness analysis of HIV prevention. Comparing a Bayesian approach with traditional deterministic sensitivity analysis

In cost-effectiveness analysis, the incremental cost-effectiveness ratio is used to measure economic efficiency of a new intervention, relative to an existing one. However, costs and effects are seldom known with certainty. Uncertainty arises from two main sources: uncertainty regarding correct values of intervention-related parameters and uncertainty associated with sampling variation. Recently, attention has focused on Bayesian techniques for quantifying uncertainty. We computed the Bayesian-based 95% credible interval estimates of the incremental cost-effectiveness ratio of several related HIV prevention interventions and compared these results with univariate sensitivity analyses. The conclusions were comparable, even though the probabilistic technique provided additional information.