摘要:

In designing a multi-product flowline, problems of material handling and workflow arise on one hand and of machine utilization on the other. Because of variations in the number of operations on parts and in their operation sequences, a sequence of machines that satisfies one particular family of parts is unlikely to satisfy all the other families. On the other hand, if a sequence is generated to accommodate all the families of parts, a simple flowline is unlikely. This is the problem of the layout of multi-product flowlines.

ISSN:0020-7543    

DOI:10.1080/00207548608919743

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

This paper deals with service level constraints which are defined over a fiscal period. Fiscal-period-based service level constraints are considerably more complex than their lead-time counterparts and result in significantly different safety stock requirements. Thus, a confusion between a lead-time and fiscal-period perspective can result in substantial financial consequences and is therefore of managerial relevance. Although no generalizations are possible from the limited results presented, further computational experience suggests that the findings reported hold over a wide range of situations.

ISSN:0020-7543    

DOI:10.1080/00207548608919744

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

This paper outlines the development of a mathematical model for predicting the system reliability of the cutting tools for an automated machining system with various carbide inserts and spares subject to Weibull failures. A numerical method using Simpson's Rule was selected as a method to address the problem of multiple integration resulting from the Weibull distribution in the spares model. A recursive algorithm was developed for predicting the system reliability of the cutting tools. This paper demonstrates the application of the developed reliability prediction model with a realistic example in the interrupted cutting process.

ISSN:0020-7543    

DOI:10.1080/00207548608919745

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

This paper presents an analytical model for determining the optimal processing-time and number of operations multiples for the TWK and TWK + NOP due-date assignment methods in a dynamic job shop subject to restrictive assumptions on queue discipline and processing time distribution. The analytical results are compared with the experimental results obtained from simulation of a hypothetical job shop under various shop conditions. The close agreement of the results reveals the validity of the analytical model. In addition, the results show that the TWK + NOP method is more effective in minimizing the missed due-date cost in a job shop.

ISSN:0020-7543    

DOI:10.1080/00207548608919746

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

This paper summarizes the development and implementation of a large-scale, multi-objective, lot-sizing model for scheduling tablet pharmaceuticals in a serial production system. The model places multiple resource capacity constraints on production at various stages of the manufacturing process and explicitly considers resource set-up times to ensure the generation of a feasible schedule. The multi-period model uniquely allows for variable lot sizes by stage and by period, subject to integrality restrictions arising from the technological nature of the multi-stage process. An integer goal programming approach is used for determining non-dominated solutions to the multi-item problem. The implementation and utilization of the model by an international manufacturer of pharmaceuticals is described, and model results are presented and discussed.

ISSN:0020-7543    

DOI:10.1080/00207548608919747

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Quality Control is perhaps not normally thought of as an area in which operational research has any contribution to make; yet, when viewed from the point of balancing inspection costs against costs of allowing defective items into the production process, it is in the mould of a typical operational research problem. Quality control is often approached via the repeated hypothesis test of classical statistics, whereby we may discuss the cost of errors of types I and II and the need to balance these costs in any inspection scheme can be discussed.

ISSN:0020-7543    

DOI:10.1080/00207548608919748

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

This paper attempts to determine the maximum number of storage and retrieval requests that can be handled by automated warehousing systems under physical and operational constraints. The system is formulated as a stochastic constrained optimization problem and an algorithm is developed for its solution. Due to the stochastic nature of the operation of the system, a simulation model is constructed to evaluate the system for various values of its parameters. The optimization routine interacts with the simulation model and systematically moves towards the optimum solution. The problem is studied under various levels of constraints. Also several levels of the risk of violation of constraints are examined.

ISSN:0020-7543    

DOI:10.1080/00207548608919749

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

A numerical method for obtaining equilibrium performance measures for a single group ofNidentical machines, each subject tok(>2) types of failures, is presented. The time intervals between breakdowns of a machine are exponentially distributed. The mean time between typeifailures is 1/&λi,i= 1, 2, ⃛, k. The service times required to repair any type of failure can be either deterministic, exponential, hypo-exponential, or hyper-exponential random variables, with different means for different types of failures. The service discipline is a non-preemptive fixed-priority rule, with different priorities assigned to different types of failures. System performance measures, such as average time spent by the machines waiting for service, average number of idle machines and machine operator utilization are obtained through imbedded Markov chain analysis. The algorithms used to obtain these measures exploit the special structure of the one-step transition probability matrix. The sensitivity of the performance measures to the density function of the service times and the priority assignments given is examined.

ISSN:0020-7543    

DOI:10.1080/00207548608919750

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Using theZ-transform method, closed-form analytical expressions for evaluating the performance of flexible manufacturing systems (FMS) are derived. The formulae are based on the operational analysis framework and allow the dependence of the performance measures on the main operational parameters to be clarified. Balanced, and nearly or completely unbalanced systems, are considered.

ISSN:0020-7543    

DOI:10.1080/00207548608919751

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

In this study, models for obtaining economic order quantities (EOQ) are considered which take into account the effects of advertising, price elasticity and economies of scale, and the possibility of some ordered items being defective. An earlier model by Subramanyam and Kumaraswamy (1981) is shown to be restrictive in its treatment of the effects of defective items. To correctly model there effects, three different scenarios for dealing with defective items are considered and the resulting EOQ models presented. Special cases are also considered. It is shown that the earlier model can lead to incorrect economic order quantities in these scenarios.

ISSN:0020-7543    

DOI:10.1080/00207548608919752

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor