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Article
Publication date: 1 February 1993

Scott M. Shafer and Jack R. Meredith

Cellular and functional layouts were investigated under a varietyof real‐world conditions via a two‐stage computer simulation study. Inthe first stage, simulation models were…

Abstract

Cellular and functional layouts were investigated under a variety of real‐world conditions via a two‐stage computer simulation study. In the first stage, simulation models were developed for three actual companies. Six different cell formation procedures were used to develop the cellular layouts and CRAFT was used to develop the functional layout. The following six variables were used to measure shop performance: average flow time, maximum flow time, average distance travelled by a batch, average work‐in‐process level, the maximum level of work‐in‐process, and the longest average queue. Factors observed in the first stage of the study that appear to make cellular manufacturing less beneficial than might otherwise be expected were found to be small batch sizes, a small number of different machines the parts require in their processing, short processing times per part, the existence of bottleneck machines (i.e. machines with insufficient capacity), and the absence of natural part families (i.e. sets of parts with similar processing requirements). In the second stage of this study, earlier assumptions associated with sequence‐dependent setup times and move time delays were relaxed. These two parameters were identified as important factors as well.

Details

International Journal of Operations & Production Management, vol. 13 no. 2
Type: Research Article
ISSN: 0144-3577

Keywords

Article
Publication date: 1 November 2002

Jiaqin Yang and Richard H. Deane

The importance of reducing product lotsizes in converting traditional job shops into just‐in‐time (JIT) type manufacturing systems has been addressed in the literature. This paper…

2138

Abstract

The importance of reducing product lotsizes in converting traditional job shops into just‐in‐time (JIT) type manufacturing systems has been addressed in the literature. This paper presents a lotsize reduction model for closed stochastic production systems. The model is formulated based on an M/G/c queuing lotsize model. Product lotsize choice is related to all major components of job flow time: waiting time in queue, batch processing time, batch moving time, and finished goods warehousing time. The research is motivated by the fact that an optimal lotsize solution that minimizes only average job waiting time in the shop may not be optimal when the effects of job batch processing time, batch moving time, and batch warehousing time are also considered. There is no general closed form solution to the model due to the complexity of its nonlinear formulation. Based on the unique properties of the model, heuristic solution procedures are developed. The research demonstrates opportunities for shop managers to significantly reduce product lotsizes while minimizing total operating cost.

Details

Integrated Manufacturing Systems, vol. 13 no. 7
Type: Research Article
ISSN: 0957-6061

Keywords

Article
Publication date: 1 March 1995

Faizul Huq and Ziaul Huq

Much of the research literature in job shop scheduling deals withpure job shop environments. However, currently most processes involve ahybrid of both the job shop and a flow shop…

1321

Abstract

Much of the research literature in job shop scheduling deals with pure job shop environments. However, currently most processes involve a hybrid of both the job shop and a flow shop with a combination of flexible and conventional machine tools. Presents a study of such a job shop under varying conditions and performance criteria. Argues that for scheduling in this environment, certain combinations of scheduling rules should be utilized under different arrival rates and for different job types. A simulation model is developed using a hypothetical hybrid job shop to study the performance of rule combinations with variations in arrival rates and processing times. The performance criteria used are flowtime as a measure of work‐in‐process inventory, tardiness for JIT, and throughput for completed items inventory. It was found that rule combination performance varied with the performance criteria. Furthermore, it was found that the combinations were sensitive to arrival rates and processing times. Concludes, from the insights gained in the study, that the rule combination to be implemented should depend on the performance objective and the arrival rate/processing time condition of the hybrid job shop.

Details

International Journal of Operations & Production Management, vol. 15 no. 3
Type: Research Article
ISSN: 0144-3577

Keywords

Article
Publication date: 10 September 2018

Ebenezer Adaku, Kwasi Amoako-Gyampah, Seth Nii Anang Lomotey, Charles Teye Amoatey and Samuel Famiyeh

The Pension Trust Company (PTC) in Ghana is the sole agency responsible for the management of the first-tier pension scheme as well as processing of claims submitted by…

Abstract

Purpose

The Pension Trust Company (PTC) in Ghana is the sole agency responsible for the management of the first-tier pension scheme as well as processing of claims submitted by beneficiaries for this scheme. The claim processing system at PTC was wrought with significant delays resulting in severe customer dissatisfaction and hardship to retirees. Hence, a new system – Age 54+ project – was developed to address the problems related to claims processing. The purpose of this paper is to report on the efficiency gains from the new claim processing system implemented at PTC and to use the philosophies behind the lean operations concept to explain the results.

Design/methodology/approach

Data for this study were obtained from the benefits system of PTC for the period 2009–2013. The data consist of a series of benefits processing time for two groups of 56,000 claimants – those cleared under the Age 54+ project and those cleared under the old processing system. The processes of the two claim processing systems were analysed and their processing times compared.

Findings

The new system – Age 54+ – decreased the average processing time for new claims by 20 per cent. The new system is a simple approach which is driven by a “Let’s Start in Time” idea.

Originality/value

The operations management literature suggests that process redesign approaches and the implementation of continuous improvement techniques represent mechanisms for achieving performance improvements at governmental agencies. This study shows and discusses the redesign of a social security scheme process using a lean operation concept of waste elimination method and application of kanban to deliver performance improvement.

Details

International Journal of Productivity and Performance Management, vol. 67 no. 7
Type: Research Article
ISSN: 1741-0401

Keywords

Article
Publication date: 1 March 2003

Fahad Al‐Mubarak, Basheer M. Khumawala and Cem Canel

This paper is aimed at comparing cellular manufacturing with focused cellular manufacturing. We define focused cellular manufacturing as a layout scheme that groups components by…

2019

Abstract

This paper is aimed at comparing cellular manufacturing with focused cellular manufacturing. We define focused cellular manufacturing as a layout scheme that groups components by end‐items and forms cells of machines to fabricate and assemble end‐items. It is not classified as a cellular manufacturing layout since it does not attempt to take advantage of process similarities. It also is not classified as a flow shop since there are no machines dedicated to individual operations and the machines are not arranged in a series. In addition, this research includes batching and assemble times in its criteria which few researchers in this area have done. The results indicate that the focused cellular manufacturing scheme has a batching advantage. This advantage out‐weighed the set‐up time reduction advantage of the cellular manufacturing scheme for average end‐item completion times and average work‐in‐process inventory levels. The cellular manufacturing scheme overcame the batching advantage only when there were small batch sizes or large set‐up time magnitudes.

Details

International Journal of Operations & Production Management, vol. 23 no. 3
Type: Research Article
ISSN: 0144-3577

Keywords

Article
Publication date: 3 April 2018

Qian Pu, Xiaomin Zhu, Donghua Chen and Runtong Zhang

This paper aims to provide an optimization method of workflow for publishing houses and electronic book (e-book) studies in the field of digital publishing.

Abstract

Purpose

This paper aims to provide an optimization method of workflow for publishing houses and electronic book (e-book) studies in the field of digital publishing.

Design/methodology/approach

Based on the studies of publishing houses in Beijing, the present conversion workflow is illustrated using a functional modeling methodology. Then, the workflow is analyzed using 5W1H (why, who, what, where, when, how) methodology and optimized using ECRSI (eliminate, combine, rearrange, simplify and increase) principles. To validate the optimization effect, the workflow before and after optimization are generated and implemented by the ExtendSim® simulation software.

Findings

The simulation results show that under similar circumstances, both quantity and quality of the products are improved after optimization, which indicate that the optimization method is effective.

Practical implications

Electronic PUBlication (EPUB) has significant requirements to satisfy the needs of the mobile reading market and to earn increased profits, whereas some e-books are still preserved in a portable document format (PDF). This study results in the enhanced EPUB quality and production efficiency of the PDF-to-EPUB format conversion workflow in publishing houses. Publishing houses around the world can refer to this study to make a similar optimization when handling PDF-to-EPUB.

Originality/value

This research introduces the traditional industrial engineering analytical techniques to the workflow optimization of e-book conversion. Compared with the most of other methods used to optimize workflow, this method is simpler, more efficient and more suitable for e-book format conversion.

Details

The Electronic Library, vol. 36 no. 2
Type: Research Article
ISSN: 0264-0473

Keywords

Article
Publication date: 1 March 2015

Anjali Kumar, Arvind Nair and Juliane Piecha

Procurement efficiency as an element of public performance management can contribute to achieving Value for Money by reducing administrative overhead costs and directing resources…

Abstract

Procurement efficiency as an element of public performance management can contribute to achieving Value for Money by reducing administrative overhead costs and directing resources to support more complex procurement processes. This paper highlights empirical techniques to understand determinants of efficiency in the procurement cycle focusing on elapsed time taken and drawing on a unique dataset on the procurement process within the World Bank. The study finds that different methods of bidding, whether international or domestic, and contract attributes partially explain differences in the duration of procurement processes.

Details

Journal of Public Procurement, vol. 15 no. 3
Type: Research Article
ISSN: 1535-0118

Article
Publication date: 1 June 1993

Scott R. Swenseth, Krishnamurty Muralidhar and Rick L. Wilson

Addresses the dynamic, continual‐improvement nature of the JITimplementation process. Learning curves are incorporated to analyse theimpact of continual reduction of processing

Abstract

Addresses the dynamic, continual‐improvement nature of the JIT implementation process. Learning curves are incorporated to analyse the impact of continual reduction of processing time variation over time. The results provide valuable information on the relationship between the level of processing time variation, the output rate of the production system, and inventory between work processes. The methodology used in this study incorporates an additional dimension in analysing JIT. It also provides a general and effective tool for decision makers facing the complex task of implementing pull production processes.

Details

International Journal of Operations & Production Management, vol. 13 no. 6
Type: Research Article
ISSN: 0144-3577

Keywords

Article
Publication date: 1 January 1995

Stuart McLean, Michael B. Spring, Edie Rasmussen and James G. Williams

The Promenade image retrieval system is described in terms of its design, development and architecture. Design, development and implementation issues are discussed in terms of…

Abstract

The Promenade image retrieval system is described in terms of its design, development and architecture. Design, development and implementation issues are discussed in terms of efficiency and effectiveness. A preliminary usability study is presented and the data respiting from the preliminary study are analysed and discussed. Efficiency in terms of response time due to network delays, database processing, application processing and image characteristics and display is discussed. Response time results from 40 queries made to the image database are presented and discussed. The results of these studies demonstrate where improvements in the system need to be made in order to improve usability and response time.

Details

The Electronic Library, vol. 13 no. 1
Type: Research Article
ISSN: 0264-0473

Article
Publication date: 27 August 2019

Nithya R.P. and Haridass M.

The purpose of this paper is to provide simulation modelling for bulk arrival bulk service queueing system involved in a textile industry and analyze the performance metrics.

Abstract

Purpose

The purpose of this paper is to provide simulation modelling for bulk arrival bulk service queueing system involved in a textile industry and analyze the performance metrics.

Design/methodology/approach

This paper describes the simulation modelling of a bulk queueing system with limited number of admissions and multiple vacations. The model is developed for the proposed queueing system using Flexsim 2017, and it is explained through an application observed in a textile industry involving the process of cone winding.

Findings

In this paper, the simulation model has been developed to study the behaviour of queues at different resources in a production system. Various performance measures such as average components, average waiting time, total number of inputs and outputs, processing time and idle time involved in a textile industry are evaluated using simulation and justified through numerical illustration.

Practical implications

The proposed simulation model may be used in various scenarios wherever a real time situation exists related to bulk queueing system. The results produced in this paper can be used by the manufacturing industries to enhance the need-based accuracy. It is worth pointing out that the findings are of direct practical relevance and can be successfully used for a number of industrial applications.

Originality/value

The approach suggested in this paper attempts to deal with the queueing system involved in a textile industry and provides numerical results in less time with less computer resources. It provides a reasonably good approximation for simple and complex queueing models where it is difficult to find closed form of theoretical results.

Details

Kybernetes, vol. 50 no. 2
Type: Research Article
ISSN: 0368-492X

Keywords

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