C.L. Hui Patrick, S.F. Ng Frency and C.C. Chan Keith
In the process of fabric spreading, the variance of fabric yardage between fabric rolls may lead to a difference in fabric loss during spreading. As there are numerous…
Abstract
In the process of fabric spreading, the variance of fabric yardage between fabric rolls may lead to a difference in fabric loss during spreading. As there are numerous combinations the arrangement of the fabric roll sequences for each cutting lay, it is difficult to construct a roll planning to minimise the fabric wastage during spreading in apparel manufacturing. Recent advances in computing technology, especially in the area of computational intelligence, can be used to handle this problem. Among the different computational intelligence techniques, genetic algorithms (GA) are particularly suitable. GAs are probabilistic search methods that employ a search technique based on ideas from natural genetics and evolutionary principles. This paper presents the details of GA and explains how the problem of roll planning can be formulated for GA to solve. The result of the study shows that an optimal roll planning can be worked out by using GA approach. It is possible to save a considerable amount of fabric when the best roll planning is used for the production.
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Keith C.C. Chan, Patrick C.L. Hui, K.W. Yeung and Frency S.F. Ng
Assembly line balancing problems that occur in real world situations are dynamic and are fraught with various sources of uncertainties such as the performance of workers and the…
Abstract
Assembly line balancing problems that occur in real world situations are dynamic and are fraught with various sources of uncertainties such as the performance of workers and the breakdown of machinery. This is especially true in the clothing industry. The problem cannot normally be solved deterministically using existing techniques. Recent advances in computing technology, especially in the area of computational intelligence, however, can be used to alleviate this problem. For example, some techniques in this area can be used to restrict the search space in a combinatorial problem, thus opening up the possibility of obtaining better results. Among the different computational intelligence techniques, genetic algorithms (GA) is particularly suitable. GAs are probabilistic search methods that employ a search technique based on ideas from natural genetics and evolutionary principles. In this paper, we present the details of a GA and discuss the main characteristics of an assembly line balancing problem that is typical in the clothing industry. We explain how such problems can be formulated for genetic algorithms to solve. To evaluate the appropriateness of the technique, we have carried out some experiments. Our results show that the GA approach performs much better than the use of a greedy algorithm, which is used by many factory supervisors to tackle the assembly line balancing problem.
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Hareton K.N. Leung, Keith C.C. Chan and Connie Poon
This paper reports the findings of a survey on 24 commercial tools for ISO 9000 certification. We analyse these tools along several dimensions: certification stages supported…
Abstract
This paper reports the findings of a survey on 24 commercial tools for ISO 9000 certification. We analyse these tools along several dimensions: certification stages supported, targeted industry sectors, and features. Each tool typically provides assistance for several stages of the certification process. Most tools provide some kinds of support for the system analysis, system implementation, system review and maintenance stages. As expected, many tools (about 33 per cent) are targeted specifically for the manufacturing sector. Another 60 per cent of the tools aim at the general business sector. Sixty per cent of the tools support assessment activities while about half support documentation template. No single tool covers all activities of the certification process. It is recommended that any company which is planning or is in the process of implementing a QMS should seriously consider the opportunity of using some of these automated tools.
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Tat Y. Lee, Hareton K.N. Leung and Keith C.C. Chan
A comprehensive survey was conducted with a view to identifying the benefits derived by ISO 9000 certified companies in Hong Kong. It is generally agreed that the certification…
Abstract
A comprehensive survey was conducted with a view to identifying the benefits derived by ISO 9000 certified companies in Hong Kong. It is generally agreed that the certification helps the companies to improve quality in terms of work procedures, product and service quality, team spirit, subcontractor control, efficiency and complaints. While a large proportion of the certified companies would like to continuously improve their quality on the basis of the certified management system, many of them do not know how to make a start. This paper reviews the difference between what is commonly known as good practice and the ISO 9000 requirements. Some recommendations are made for the certified companies which are planning to develop their quality journey based on ISO 9000.
Hareton K.N. Leung, Keith C.C. Chan and T.Y. Lee
This paper presents the result of a study to identify the costs and benefits of obtaining ISO 9000 certification. Toward this goal, a survey of some 500 ISO 9000 certified…
Abstract
This paper presents the result of a study to identify the costs and benefits of obtaining ISO 9000 certification. Toward this goal, a survey of some 500 ISO 9000 certified companies has been carried out. Among them, more than 65 per cent believe that ISO 9001 certification is worthwhile, and more than 76 per cent believe that the cost of certification is inexpensive. The results indicate that companies which seek certification because of their customers’ request seem to gain less benefit from ISO 9000 certification. We also found that concern for high costs is much less after initial certification. In addition, we discovered that contrary to many people’s expectation, some factors do not have any bearing on whether benefits outweigh costs. These factors include time taken to get certified, number of years since certification, and reason for certification. Besides presenting the results of the survey, we also introduce a new classification scheme based on the company’s view on the “expensiveness” of the certification and the received benefits. There are some differences in responses from companies of different classes.
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Patrick C.L. Hui, Keith C.C. Chan, K.W. Yeung and Frency S.F. Ng
This paper aims to investigate the use of artificial neural networks (ANN) to predict the sewing performance of fabrics. The purpose of this study is to verify the ANN techniques…
Abstract
Purpose
This paper aims to investigate the use of artificial neural networks (ANN) to predict the sewing performance of fabrics. The purpose of this study is to verify the ANN techniques that could be emulated as human decision in the prediction of sewing performance of fabrics.
Design/methodology/approach
In order to verify the ANN techniques that could be emulated as human decision in the prediction of sewing performance of fabrics, 109 data sets of fabrics were tested by using fabric assurance by simple testing system and the sewing performance of each fabric's specimen was assessed by the domain experts. Of these 109 input‐output data pairs, 94 were used to train the proposed backpropagation (BP) neural network for the prediction of the unknown sewing performance of a given fabric, and 15 were used to test the proposed BP neural network.
Findings
After 10,000 iterations of training of BP neural network, the neural network converged to the minimum error level. The experimental results reveal the great potential of the proposed approach in predicting the sewing performance of fabrics for apparel production.
Originality/value
Generally, the fabric's performance in the manufacturing process is judged subjectively by the operators and/or their supervisors. Current methodologies of acquiring fabric property information and predicting fabric sewing performance are still incapable of providing a means for efficient planning and control for the sewing operation. Further, development of techniques to predict the sewing performance of fabric is essential for the current apparel production environment. In this paper, the use of ANN to predict the sewing performance of fabrics in garment manufacturing is investigated.
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Yu-Chung Tsao, Chia-Chen Liu, Pin-Ru Chen and Thuy-Linh Vu
In recent years, the demand for garments has significantly increased, requiring manufacturers to speed up their production to attract customers. Cut order planning (COP) is one of…
Abstract
Purpose
In recent years, the demand for garments has significantly increased, requiring manufacturers to speed up their production to attract customers. Cut order planning (COP) is one of the most important processes in the apparel manufacturing industry. The appropriate stencil arrangement can reduce costs and fabric waste. The COP problem focuses on determining the size combination for a pattern, which is determined by the length of the cutting table, width, demand order, and height of the cutting equipment.
Design/methodology/approach
This study proposes new heuristics: genetic algorithm (GA), symbiotic organism search, and divide-and-search-based Lite heuristic and a One-by-One (ObO) heuristic to address the COP problem. The objective of the COP problem is to determine the optimal combination of stencils to meet demand requirements and minimize the total fabric length.
Findings
A comparison between our proposed heuristics and other simulated annealing and GA-based heuristics, and a hybrid approach (conventional algorithm + GA) was conducted to demonstrate the effectiveness and efficiency of the proposed heuristics. The test results show that the ObO heuristic can significantly improve the solution efficiency and find the near optimal solution for extreme demands.
Originality/value
This paper proposes a new heuristic, the One-by-One (ObO) heuristic, to solve the COP problem. The results show that the proposed approaches overcome the long operation time required to determine the fitting arrangement of stencils. In particular, our proposed ObO heuristic can significantly improve the solution efficiency, i.e. finding the near optimal solution for extreme demands within a very short time.
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Melissa G. Keith, Peter D. Harms and Alexander C. Long
Despite widespread interest in the gig economy, academic research on the topic has lagged behind. The present chapter applies organizational theory and research to compose a…
Abstract
Despite widespread interest in the gig economy, academic research on the topic has lagged behind. The present chapter applies organizational theory and research to compose a working model for understanding participation in the gig economy and how gig work may impact worker health and well-being. Drawing from past research this chapter defines the gig economy in all its diversity and advances a framework for understanding why individuals enter into gig economy. Next, the authors discuss how various characteristics of the gig economy and gig workers can be understood as both demands and resources that influence how gig work is likely to be experienced by the individual. To understand how these characteristics are likely to influence worker health and well-being, we draw from past research on alternative work arrangements and entrepreneurship, as well as the limited extant research on the gig economy. Finally, a research agenda is proposed to spur much needed research on the gig economy and its workers.
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Aim of the present monograph is the economic analysis of the role of MNEs regarding globalisation and digital economy and in parallel there is a reference and examination of some…
Abstract
Aim of the present monograph is the economic analysis of the role of MNEs regarding globalisation and digital economy and in parallel there is a reference and examination of some legal aspects concerning MNEs, cyberspace and e‐commerce as the means of expression of the digital economy. The whole effort of the author is focused on the examination of various aspects of MNEs and their impact upon globalisation and vice versa and how and if we are moving towards a global digital economy.
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The purpose of this paper is to examine the information content in the Standard & Poor (S&P) 500 index revision and its impact on the corporate bonds and earnings of the firms…
Abstract
Purpose
The purpose of this paper is to examine the information content in the Standard & Poor (S&P) 500 index revision and its impact on the corporate bonds and earnings of the firms whose stocks are added to or deleted from the index.
Design/methodology/approach
The paper uses panel regressions on a 13-year sample of the companies added and deleted from the S&P 500 index.
Findings
The regression results on the bond yields and earnings show that analysts and investors draw positive (negative) information from Index additions (deletions) and adjust their expectations of the firm performance as well as the required rates of return on corporate bonds after index revisions.
Research limitations/implications
The paper suggests that deletions from the Index have significantly negative impacts on corporate bonds and earnings performance of deleted firms while additions to the index do not have significant impacts on the bonds or realized earnings of added firms.
Originality/value
This paper uses corporate bonds and earnings to test competing hypotheses proposed to explain the excess stock returns of index revision, including information content hypothesis and liquidity hypothesis. The results are consistent with the information content hypothesis and do not support the liquidity hypothesis.