摘要:

We investigated the effect of supplier and process uncertainty in a real time MRP environment. The environment modelled is supported by an ‘on line’ data monitoring and data collection system such that the activities of the shop floor and the receiving area are incorporated within the MRP database as they occur. The purpose of the model is to evaluate the operation of an integrated shop floor control/M R P system in a multi-level product structure environment which operates on a rolling horizon basis. The interaction of supply/process uncertainty with product structure and choice of lot sizing rule is examined for various cost factors. The presence of uncertainty is found to greatly complicate the operation of the MRP system. In addition, supply/process uncertainty combines with product structure and the choice of lot sizing rule, to impact the cost performance of the system. The significance of these interactions was confirmed by the formulation and testing of several hypotheses. Based on these results, some practical interpretations are also presented.

ISSN:0020-7543    

DOI:10.1080/00207549508930144

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Organisational coordination on the firm's strategic objectives is essential to compete effectively in the global economy. A systematic approach is needed to synchronize the firm's activities in relation to its objectives. Integrated performance measurement systems provide a vehicle for improved organisational coordination. The purpose of this exploratory research was to examine the integrated performance measurement systems of six manufacturing firms identified as world class by academic and practitioner experts. A case study methodology was used to collect detailed information on division and plant strategic objectives, performance measurement systems, and performance measurement system linkages. The result of this research was the development of principles on strategic objectives, performance measurement systems and performance measurement system linkages for improved organisational coordination.

ISSN:0020-7543    

DOI:10.1080/00207549508930145

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

We investigated the feasibility of using stochastic Petri nets (SPNs) to describe the behaviours of automated storage/retrieval systems as well as to evaluate the performance of different control policies of such systems. SPNs have been studied in the past 2 decades, and have become a powerful tool in modelling concurrent and distributed systems that exhibit synchronization and contention of shared resources. It appeared that some important characteristics of AS/RS could be well modelled with SPNs. The SPN is a graph-based tool suitable for modelling systems (manufacturing, computer, biological, etc.). It can be used to model a system at different levels of abstraction. In this study, the efficiency, control rules, bay assignment, and many other performance issues associated with AS/RS have been studied in detail using SPN models. SPNs are shown to be equivalent to the stochastic processes in which embedded Markov chains can be recognized. In addition, a stochastic Petri net package, SPNP, was adopted to solve the reachability trees from which an embedded Markov chain was generated. Finally, the performance of those systems of our interest was evaluated. The unique features and flexibility of SPNs are presented. Furthermore, the SPN models for different control algorithms of an AS/RS are discussed with examples.

ISSN:0020-7543    

DOI:10.1080/00207549508930146

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Productivity and quality are an integrated component of the operational strategy of any firm. An increase in productivity implicitly assumes an improvement in quality. The concept of dynamic process quality control and smaller lot-size production have been employed to eliminate defective items, to reduce the cycle time of a product and to improve quality and productivity. We present a mathematical model to establish the relationship between various parameters of productivity and quality. In addition, the proposed model is used to determine the optimal levels of productivity and quality parameters such as batch sizes, and investment in set-up and process control operations. The basic criterion considered for optimizing the level of such parameters is the minimization of total system cost. The proposed model relates productivity and quality to set-up reduction, queueing of batches, batch sizes, and drift rate reduction. We conclude with an example problem to illustrate the behaviour and application of the model.

ISSN:0020-7543    

DOI:10.1080/00207549508930147

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

This study compares alternative shop loading procedures for cellular and functional layouts in a variety of operating environments. Factors investigated here include: (1) the extent to which the parts in a family follow a unidirectional flow; (2) shop congestion level; (3) the magnitude of delays in moving batches between departments; and (4) whether the shop was labour constrained. Computer simulation was used to compare the combinations of shop layout and loading procedure on the basis of time in system. Important managerial implications are presented for selecting a layout and loading procedure given the operating environment.

ISSN:0020-7543    

DOI:10.1080/00207549508930148

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

ISSN:0020-7543    

DOI:10.1080/00207549508930149

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor