摘要:

In this study we examine the elements that affect the required capacity of a warehouse in a stochastic environment. The required capacity is measured in terms of its deviation from the nominal capacity requirement (NCR). A simulation model was developed to measure the relationship between warehouse capacity and the various pertinent parameters. From a set of simulated experiments, it is seen that the deviation in the required capacity is mainly affected by the number of items stored, the ordering quantity and the average issues of items per day.

ISSN:0020-7543    

DOI:10.1080/00207548808947999

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

This paper presents an argument that since the proportion of product cost which represents direct labour is diminishing and the material content cost is increasing, western firms are shifting their production management paradigm from one of maximizing the utilization of capacity to one of minimizing the need for inventory. With this shift in management emphasis is coming the acceptance of unavoidable idle time at some work stations. This paper presents a mixed integer linear programming formulation which optimizes the sequence of jobs through a single facility and which places the correct amount of idle time between jobs to minimize the sum of earliness and tardiness penalties. Although this formulation reaches an optimal solution in every instance, the computation lime required was found to grow in an exponential manner as the number of jobs considered increased. Given the cost of computing at present, there appears to be a need for more computationally efficient heuristics to solve this problem.

ISSN:0020-7543    

DOI:10.1080/00207548808948000

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Surface finish data were generated for aluminium alloy 390, ductile cast iron, medium carbon leaded steel 10L45, medium carbon alloy steel 4130, and inconel 718 for a wide range of machining conditions defined by cutting speed, feed and tool nose radius. These data were used to develop surface finish prediction models, as a function of cutting speed, feed, and tool nose radius, for each individual metal. A general purpose surface finish prediction model is also proposed for ductile cast iron, medium carbon leaded steel, and alloy steel. Statistical analysis of experimental data indicated that surface finish is strongly influenced by the type of metal, speed and feed of cut, and tool nose radius. While the effects of feed and tool nose radius on surface finish were generally consistent for all materials, the effect of cutting speed was not. The surface finish improved with speed for ductile cast iron, medium carbon leaded steel, medium carbon alloy steel, and aluminium alloy, but it deteriorated with speed for inconel. Apparently, speed effect on surface finish is not always positive. For all metals, the surface finish improved with the tool nose radius while it deteriorated with speed.

ISSN:0020-7543    

DOI:10.1080/00207548808948001

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

An occurrence-based service-level constraint, defined over a fiscal period, is introduced. This service-level constraint measures the actual number of stockout episodes and restricts it to a managerially acceptable level. It is shown that the solution to the emerging chance-constrained inventory problem is independent of the type and parameters of the demand distribution. The approach is demonstrated and its managerial implications, in particular with respect to reorder points, are discussed.

ISSN:0020-7543    

DOI:10.1080/00207548808948002

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

In the near future many companies will face the problem of the optimal use of newly installed manufacturing technology (e.g. a flexible manufacturing system or FMS). Very often this will involve decisions on what parts to produce using the new system (the part mix problem) and how to produce these parts (the routing mix problem). We show that traditional operational research tools such as linear programming and queueing network theory are well suited to tackle these problems. In particular, LP models are combined with queueing network models in an iterative procedure. As such the strengths of both techniques can be exploited in making optimal use of the part mix and routing mix flexibility of the FMS.

ISSN:0020-7543    

DOI:10.1080/00207548808948003

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

An algorithm for the near real-time dispatching and routeing for multiple product assembly in a Flexible Assembly System (FAS) is described and initial test results are reported. The description of the FAS environment is drawn from an actual installation for which the algorithm design was intended.

ISSN:0020-7543    

DOI:10.1080/00207548808948004

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Computerized visual inspection systems are increasingly being considered and implemented as an alternative to manual inspection and manual gauging in manufacturing systems. Although computer vision systems and image processing have received much attention in the past, statistically powerful, yet computationally efficiency methods still remain to be developed to process the visual information to make computerized inspection systems cost effective. This study investigates the case of inspecting round production parts for shape and size. The statistical properties of the out-of-roundness measurement procedure are investigated. Real-time implementation considerations are discussed.

ISSN:0020-7543    

DOI:10.1080/00207548808948005

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A stochastic multistage production/inventory problem can be solved by an approximate procedure developed by Clark and Scarf. Previous researchers have made comparisons of the solutions obtained by this procedure with optimal solutions obtained by a Markov Decision Process (MDP) solution procedure and found that the Clark-Scarf procedure gives close to optimal solutions. Their experimentation was restricted to two-stage problems. In this paper we extend the comparison to three-stage problems. It is found that the differences in average costs per period grow noticeably as the number of stages of the problem increases. Observations that may facilitate the development of a heuristic procedure to improve the Clark-Scarf solution are given.

ISSN:0020-7543    

DOI:10.1080/00207548808948006

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The control of an equipment-intensive production system in the electronics industry is a very complicated task due to the complex process flow, especially the necessity for several loop sequences of the same processes.

ISSN:0020-7543    

DOI:10.1080/00207548808948007

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

This report proposes a method of estimating the amount of safety stock needed in each station of a production line due to variation in processing times, machine breakdowns and demand fluctuation in order to meet a predetermined desired level of performance. The production line is assumed to operate as a pull system and the measure of performance is the average percentage of demand backlogged. Multiple machines and different batch sizes in the stations are included in the model. Dynamic production control is used and is based on the current inventory level in every station of the system. Simulation results are used to test the performance of the system in which the maximum inventory level allowed in each station is based on the estimation given by our method.

ISSN:0020-7543    

DOI:10.1080/00207548808948008

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor