摘要:

AbstractMost information systems generate large quantities of figures—usually at the request of senior management. Their interpretation is frequently left to the user management. Sales information systems are particularly prone to producing vast quantities of computer print-out. This paper describes a case study within Lyons Bakery Ltd where statistical methods have been incorporated into a standard sales information system in order to isolate sales problems and provide a lay interpretation of their causes, leaving management free to devise and implement their solutions.

ISSN:0160-5682    

DOI:10.1057/jors.1978.160

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

AbstractThis paper offers an example of a practical production planning system as used routinely by BP Chemicals Ltd. It is based on the interactive control of a linear programming model embedded in a system for data collection and report production. The model solves a "product mix" type of problem with a multi-criteria objective function.

ISSN:0160-5682    

DOI:10.1057/jors.1978.161

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

AbstractThe operational characteristics of U.K. container terminals and shipping services are reviewed in relation to their effect on the use of queue models in decisions on investment in berth construction and cargo handling equipment. Some simple queue models for a new container service are evaluated, showing the importance of interpreting the choice of parameters and results of these models in relation to the particular costs and requirements of container operations and how this ranks investment options differently to the traditional application of queue models to port investment. This ranking is compared with the actual decision made and the effects of some other factors not included in the models noted.

ISSN:0160-5682    

DOI:10.1057/jors.1978.162

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

AbstractUrban planners are often involved in the determination of where recreational facilities (i.e. pools, gymnasia, tennis courts, etc.) should be located within the city. This problem is complicated by the planners' desire to realize certain goals in the allocation process. They desire to build only facilities for which there are sufficient construction funds and which can be operated within a predetermined budget. In addition they desire to satisfy the demands of the residents of the city for different facilities. However, these demands are often conflicting since many urban areas are somewhat segregated with the inner city being predominantly minority/lower income and the outer city consisting of white/upper income groups. These different groups enjoy different types of recreation, and, thus, demand different facilities. Since this is basically an allocation problem with multiple conflicting objectives, goal programming surfaces as an appropriate solution technique. This paper describes an integer (0-1) goal programming model for the recreational allocation problem and demonstrates its use via a case example. The model results specify the facilities which should be constructed that best meet the conflicting goals.

ISSN:0160-5682    

DOI:10.1057/jors.1978.163

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

AbstractA dynamic programming model for deciding when optimally to maintain, rebuild or replace aging machines is presented. The model considers maintenance and rebuild costs, tax depreciation, opportunity costs due to lost production capacity, and a number of other factors. Linear programming and enumeration are employed to obtain optimal policies and to test the sensitivity of these optimal policies to the various factors. The model is applied to two actual problems involving barges and mining equipment.

ISSN:0160-5682    

DOI:10.1057/jors.1978.164

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

AbstractThe paper describes a modified "wait-and-see" approach to solving two-stage stochastic programming problems. The approach, which involves a detailed sensitivity analysis in the classical sense, is described within the frameworks of decision theory and probabilistic programming. Although optimality in the mathematical sense cannot be guaranteed by using the approach, it is suggested that the managerial benefits weigh heavily in its favour. The approach allows management to consider a wide variety of objectives in making the choice between alternatives and facilities detection of the cause of any infeasibility due to management policy constraints. In addition, it allows much simpler programming calculations and provides an upper bound on the benefits that can be obtained by solving the full "here-and-now" problem and thus a judgement of the worth of the added computational burden can easily be made.

ISSN:0160-5682    

DOI:10.1057/jors.1978.165

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

AbstractThis paper deals with determining an optimal sequence of service stations in a series queueing system. Optimality is defined in terms of the total time spent waiting for service. Sequences are compared on the basis of the moments of their steady-state total waiting time. In addition, the rules of stochastic dominance are applied which allow comparison of sequences on the basis of their waiting time distributions. Analytical results in the sequencing of service stations in series queues have been limited to stations with constant or exponential service times. This study extends the investigation to service distributions with varying degrees of statistical regularity given by the family of Erlang distributions.Relationships are developed for predicting optimal sequences. Validation is accomplished by simulating a number of systems and comparing the waiting time distribution functions for each sequence. The relationships are shown to be good predictors and useful in the study and design of systems of servers in series.

ISSN:0160-5682    

DOI:10.1057/jors.1978.166

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

AbstractInformation systems have become increasingly complex over recent years, underscoring the challenge of designing systems which will provide the different functions in an organization with the information necessary for effective decision-making. With rapidly developing computer technology, it is natural that information systems evolve in a manner which is greatly dependent on computing hardware and software. Yet, there has been little development in the techniques of systems analysis and design to handle new and less well-understood functions which are of increasing interest.This paper demonstrates an application of structural modelling concepts to decision-support system synthesis. With the aid of the computer, structural modelling serves as an effective tool for: (1) partitioning a system into a set of subsystems; (2) specifying subsystems sufficiently to permit separate testing before total system tests; (3) eliminating redundant control information flow; and (4) facilitating decision-maker and system-analyst coordination and participation in the design process.

ISSN:0160-5682    

DOI:10.1057/jors.1978.167

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

AbstractRecently published mathematical expressions for measures of performance in a stock replenishment system are examined. The representation of service level is different from others in the literature. The difference in average stock is shown to be negligible in most practical cases.

ISSN:0160-5682    

DOI:10.1057/jors.1978.168

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

AbstractSometimes one or more constraints seriously affect the optimization of an objective function and therefore some relaxation of the constraints is desired if possible. It is assumed that constraints can be relaxed at the cost of introducing some penalty functions into the objective function. In some cases the optimization of the modified objective function (which includes penalty functions) subject to optimally relaxed constraints is preferred. This note deals with the optimal relaxation of the constraints with regard to the linear programming problem which consequently results in overall optimization.

ISSN:0160-5682    

DOI:10.1057/jors.1978.169

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor