摘要:

AbstractProfessor Ackoff's planning paradigm of participation, continuity and holism is reviewed in terms of the practical problems of attempting to implement these ideal principles. His proposal of using the paradigm to design ideal-seeking systems is compared with the market-based approaches advocated by Professor Friedman. That comparison draws on Professor Hirsch's critique of the efficiency and moral content of the market and uses that critique on Professor Ackoff's suggested alternatives.

ISSN:0160-5682    

DOI:10.1057/jors.1980.161

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

AbstractThe fundamental assumption in the classical Economic Batch Quantity model is that the products which are manufactured by a company have demands which are independent of each other. In an assembly operation, the demand for the components is mainly due to the demand for the parent assembly and hence the classical model is not applicable. In such a situation, requirements planning methodology may be successfully employed. A case study is described in this paper in which a number of factors besides set-up and stock-holding costs are considered. The results have proved to be of considerable benefit to the company.

ISSN:0160-5682    

DOI:10.1057/jors.1980.162

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

AbstractThe problem of producing financial plans for the subsidiary of a multinational corporation is one which is critical, especially in uncertain times. In addition there is always a pressing time constraint. This paper describes a suite of models which are in use by Caltex Oil South Africa to assist in this area. The approach adopted was to provide simple models which work interactively. The financial planning analysts were able to be very involved in the project because a high level modelling language was used which they could easily comprehend. The tremendous benefits of this type of approach in terms of user acceptance and in other areas are examined.

ISSN:0160-5682    

DOI:10.1057/jors.1980.163

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

AbstractStock level frequency distributions are derived for continuous review stock control policies in which the lead time demand is normally distributed. The percentage points of the distributions have been tabulated, and the table can be used to determine the reorder point that will meet a specified customer order quantity from stock with a specified probability. The results can also be used to determine the order up to point for a periodic review policy and the reorder point for a mixed policy.

ISSN:0160-5682    

DOI:10.1057/jors.1980.164

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

AbstractThis paper reports a case study carried out in an Engineering industry manufacturing nineteen types of products against orders. The objective of this research was to select the sequencing rule that will optimise the combined performance of work-in-process inventory in monetary terms and delivery performance. Past studies in this area show that rules based on either the value of the orders or the value-processing time of the orders have not been investigated. This study evaluates the performance of the two sequencing rules based on the value and processing time of the orders: (i) Lowest Value Time rule (LVT) (ii) Highest Value Time rule (HVT). Incidental to this study, a few other sequencing rules were evaluated. To carry out the investigations, a simulator using GPSS (General Purpose Simulation System) was developed.

ISSN:0160-5682    

DOI:10.1057/jors.1980.165

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

AbstractThe paper describes a class of models rather more general than the ARIMA processes of Box and Jenkins, and surveys recently achieved results for their serial dependence behaviour. These properties are obtained analytically, from simulation and by direct computation-either approximately or exactly. The paper concentrates on the expectations of serial covariances and the problem of distinguishing between nearly non-stationary models and homogeneous non-stationary approximations to them-in particular, for a specific pair of ARMA(1,1) and IMA(1,1) processes.

ISSN:0160-5682    

DOI:10.1057/jors.1980.166

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

AbstractThis paper considers theM/G/kblocking system under the assumption of servers whose service time distributions differ. Such a system haskservers each with a (possibly) different service time distribution, whose customers arrive in accordance with a Poisson process. They are served, unless all the servers are occupied. In this case they leave and do not return later (i.e. they are "blocked"). A generalization of the ErlangB-formula is given and it is shown that the latter is valid in the case of heterogeneous servers too, provided that all servers have equal mean service times. In the form of an appendix, the Engset formula also is generalized under the above assumption.

ISSN:0160-5682    

DOI:10.1057/jors.1980.167

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

AbstractA time series modelling approach is suggested to analyze the set of performance deviations which are generated by the institution's control system. The purpose of the time series analysis is to provide decision makers with information regarding the structure underlying the set of performance deviations. This structural analysis is intended to facilitate the selection and implementation of appropriate control actions. The basic control system's elements needed to generate information amenable to a time series analysis are specified. A simple case is presented to illustrate the time series method suggested.

ISSN:0160-5682    

DOI:10.1057/jors.1980.168

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

AbstractFor the statistical description of a demand process, many probability density functions (pdf) are available, each having its advantages and drawbacks. How do they compare when in application? Is it true that the shape of the pdf is not relevant? This paper deals with one application, namely a simple s,Q stock control system. Assuming for the lead time demand successively five different pdf's (Gaussian, logistic, gamma, log-normal, Weibull) and using the service level as a criterion, it is shown that for this application (1) the numerical differences between the selected functions are in fact negligible; (2) the logistic pdf produces a formula that only contains elementary transcendental functions; (3) the other pdf's lead to much more complex expressions.

ISSN:0160-5682    

DOI:10.1057/jors.1980.169

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

AbstractA method is described for finding a minimum cost set of schedules for railway locomotives to work a given set of trains. The times at which the trains start may be fixed or variable. A heuristic method, based on a linear programming model, is described. This gives good integer solutions to the problem.

ISSN:0160-5682    

DOI:10.1057/jors.1980.170

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor