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1 – 10 of over 2000Binghai Zhou and Qiong Wu
The balancing of robotic weld assembly lines has a significant influence on achievable production efficiency. This paper aims to investigate the most suitable way to assign both…
Abstract
Purpose
The balancing of robotic weld assembly lines has a significant influence on achievable production efficiency. This paper aims to investigate the most suitable way to assign both assembly tasks and type of robots to every workstation, and present an optimal method of robotic weld assembly line balancing (ALB) problems with the additional concern of changeover times. An industrial case of a robotic weld assembly line problem is investigated with an objective of minimizing cycle time of workstations.
Design/methodology/approach
This research proposes an optimal method for balancing robotic weld assembly lines. To solve the problem, a low bound of cycle time of workstations is built, and on account of the non-deterministic polynomial-time (NP)-hard nature of ALB problem (ALBP), a genetic algorithm (GA) with the mechanism of simulated annealing (SA), as well as self-adaption procedure, was proposed to overcome the inferior capability of GA in aspect of local search.
Findings
Theory analysis and simulation experiments on an industrial case of a car body welding assembly line are conducted in this paper. Satisfactory results show that the performance of GA is enhanced owing to the mechanism of SA, and the proposed method can efficiently solve the real-world size case of robotic weld ALBPs with changeover times.
Research limitations/implications
The additional consideration of tool changing has very realistic significance in manufacturing. Furthermore, this research work could be modified and applied to other ALBPs, such as worker ALBPs considering tool-changeover times.
Originality/value
For the first time in the robotic weld ALBPs, the fixtures’ (tools’) changeover times are considered. Furthermore, a mathematical model with an objective function of minimizing cycle time of workstations was developed. To solve the proposed problem, a GA with the mechanism of SA was put forth to overcome the inferior capability of GA in the aspect of local search.
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M. Bevilacqua, F.E. Ciarapica, I. De Sanctis, G. Mazzuto and C. Paciarotti
The purpose of this paper is to uncover the significance of quick changeovers in the packaging line of a pharmaceutical company. Using an integration of different lean practices…
Abstract
Purpose
The purpose of this paper is to uncover the significance of quick changeovers in the packaging line of a pharmaceutical company. Using an integration of different lean practices, the study aims to reduce the batch change and changeover time up to 50 per cent, increasing overall equipment effectiveness by 25 per cent.
Design/methodology/approach
The paper gives setup instructions and guidelines for preparing the standardized setup procedure without ignoring the actual constraints in a pharmaceutical company. It uses a case study to generate an integrated setup reduction approach, utilizing single-minute exchange of die tools (SMED) in combination with suppliers, inputs, process, outputs and customers (SIPOC), Kanban, 5S techniques and Total Productive Maintenance (TPM) indexes to achieve faster setups.
Findings
The SMED approach helps the pharmaceutical company to eliminate unwanted activities and to externalize and reduce the internal activities by simplification or standardization. The application of other tools, such as 5S and Kanban tool-kits, allowed the company to optimize the process and reduce the standard deviation of the changeover times. Good manufacturing practice (GMP) procedures of the pharmaceutical sector limit the conversion of internal setup elements to external setup elements.
Originality/value
The paper demonstrates the practical application of SMED, showing how it can bring real breakthroughs in productivity to a pharmaceutical company. Moreover, in this work, we highlight the importance of an integration of different lean practices to reduce variation in the changeover time. In particular, the standardization of setup tasks and the increased reliability in the material supply chain, in addition to reducing the changeover mean time can also reduce the standard deviation of the setup process time.
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Syed Mithun Ali, Muhammad Najmul Haque, Md. Rayhan Sarker, Jayakrishna Kandasamy and Ilias Vlachos
Bangladesh's ready-made garment (RMG) industry plays a vital role in the economic growth of this country. As the global trend in the fashion market has introduced a high-mix…
Abstract
Purpose
Bangladesh's ready-made garment (RMG) industry plays a vital role in the economic growth of this country. As the global trend in the fashion market has introduced a high-mix, low-volume ordering style, manufacturers are facing an increased number of changeovers in their production systems. However, most of the Bangladeshi RMG manufacturers are not yet ready to respond to such small orders and to improve the flexibility of their production systems. Consequently, the industry is falling behind in global market competition. Thus, this study aims to advance the current performance of RMG manufacturing operations to respond to the fast-fashion industry's challenges effectively using quick changeover.
Design/methodology/approach
In this study, a Single-Minute Exchange of Dies (SMED) is applied to attain quick changeover following the best practices of lean manufacturing.
Findings
This study examined the performance of the SMED technique to reduce changeover time in two case organisations. The changeover time was reduced by 70.76% from 434.56 min to 127.08 min and 42.12% from 2,664 min to 1,542 min for the case organisations, respectively. The results of this study show that companies require improved changeover times to address the demand for high-mix, low-volume orders.
Originality/value
This study will certainly guide practitioners of the RMG industry to adopt SMED to reduce changeover time to meet small batch production.
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Richard McIntosh, Steve Culley, Graham Gest, Tony Mileham and Geraint Owen
Discusses the derivation of current changeover improvement methodologies from the work of the Japanese engineer/consultant Shigeo Shingo. Argues that under the interpretation and…
Abstract
Discusses the derivation of current changeover improvement methodologies from the work of the Japanese engineer/consultant Shigeo Shingo. Argues that under the interpretation and widespread adoption of the single minute exchange of dies (SMED) philosophy, substantive design‐based solutions are being overlooked in favour of incremental, low cost, team‐based approaches which emphasize organizational changes to the changeover. Identifies difficulties which can arise with existing approaches to changeover improvement and the relative merits of emphasis on design or organization are discussed. Pays particular attention to the problems which have been observed in sustaining levels of improvement.
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Marcello Braglia, Francesco Di Paco, Marco Frosolini and Leonardo Marrazzini
This paper presents Quick Changeover Design (QCD), which is a structured methodological approach for Original Equipment Manufacturers to drive and support the design of machines…
Abstract
Purpose
This paper presents Quick Changeover Design (QCD), which is a structured methodological approach for Original Equipment Manufacturers to drive and support the design of machines in terms of rapid changeover capability.
Design/methodology/approach
To improve the performance in terms of set up time, QCD addresses machine design from a single-minute digit exchange of die (SMED). Although conceived to aid the design of completely new machines, QCD can be adapted to support for simple design upgrades on pre-existing machines. The QCD is structured in three consecutive steps, each supported by specific tools and analysis forms to facilitate and better structure the designers' activities.
Findings
QCD helps equipment manufacturers to understand the current and future needs of the manufacturers' customers to: (1) anticipate the requirements for new and different set-up process; (2) prioritize the possible technical solutions; (3) build machines and equipment that are easy and fast to set-up under variable contexts. When applied to a production system consisting of machines subject to frequent or time-consuming set-up processes, QCD enhances both responsiveness to external market demands and internal control of factory operations.
Originality/value
The QCD approach is a support system for the development of completely new machines and is also particularly effective in upgrading existing ones. QCD's practical application is demonstrated using a case study concerning a vertical spindle machine.
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Azim Mohammad, Abu Hamja and Peter Hasle
Shorter lead time with low price and quality product demand is pivotal in the garment industry. Pressure on production lead time stresses the importance of reducing style…
Abstract
Purpose
Shorter lead time with low price and quality product demand is pivotal in the garment industry. Pressure on production lead time stresses the importance of reducing style changeover time in manufacturing factories, and this paper aims to contribute to solving the challenge by showing how the single minute exchange of die (SMED) methodology in practice can be adapted to garment factories in developing countries.
Design/methodology/approach
The paper investigates three cases of SMED implementation integrated with responsible, accountable, consulted, informed (RACI) matrices in garment factories in an action research approach. Both quantitative and qualitative methods are applied.
Findings
The study shows a reduction of 50% to 64% of changeover time with SMED implementation measured with two key indicators – throughout time and time to reach peak production. Moreover, the implementation depends on the application of the RACI matrix for the distribution of responsibility as well as integration with the basic production flow before and after the application of SMED.
Practical implications
The study can guide better SMED implementation in garment factories with limited investment by stressing the need to adapt to the specifics of the garment industry, secure the division of responsibility and integrate SMED in the production flow before and after the changeover.
Originality/value
Limited research on the application of SMED in the garment industry. This paper contributes to understanding the specific conditions for successful implementation in the garment industry in developing countries and addresses additional activities that help secure a sustainable implementation process.
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Binghai Zhou and Qiong Wu
The extensive applications of the industrial robots have made the optimization of assembly lines more complicated. The purpose of this paper is to develop a balancing method of…
Abstract
Purpose
The extensive applications of the industrial robots have made the optimization of assembly lines more complicated. The purpose of this paper is to develop a balancing method of both workstation time and station area to improve the efficiency and productivity of the robotic assembly lines. A tradeoff was made between two conflicting objective functions, minimizing the number of workstations and minimizing the area of each workstation.
Design/methodology/approach
This research proposes an optimal method for balancing robotic assembly lines with space consideration and reducing robot changeover and area for tools and fixtures to further minimize assembly line area and cycle time. Due to the NP-hard nature of the considered problem, an improved multi-objective immune clonal selection algorithm is proposed to solve this constrained multi-objective optimization problem, and a special coding scheme is designed for the problem. To enhance the performance of the algorithm, several strategies including elite strategy and global search are introduced.
Findings
A set of instances of different problem scales are optimized and the results are compared with two other high-performing multi-objective algorithms to evaluate the efficiency and superiority of the proposed algorithm. It is found that the proposed method can efficiently solve the real-world size case of time and space robotic assembly line balancing problems.
Originality/value
For the first time in the robotic assembly line balancing problems, an assignment-based tool area and a sequence-based changeover time are took into consideration. Furthermore, a mathematical model with bi-objective functions of minimizing the number of workstations and area of each station was developed. To solve the proposed problem, an improved multi-objective immune clonal selection algorithm was proposed and a special coding scheme is designed.
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Shellyanne Wilson and Nazma Ali
Mix flexibility is a critical manufacturing flexibility type needed to produce a company's range of products. Oftentimes, multiple products are produced on shared resources which…
Abstract
Purpose
Mix flexibility is a critical manufacturing flexibility type needed to produce a company's range of products. Oftentimes, multiple products are produced on shared resources which require coordination mechanisms to ensure their effective utilization. This paper aims to explore the applicability of the product wheel concept as a coordination mechanism that can be used to manage shared resources in operational mix flexibility achievement in process industries.
Design/methodology/approach
The product wheel concept is a construct from the theory of lean manufacturing adoption in process industries. This construct is applied as a sequencing coordination mechanism, where similar products are grouped together to run consecutively in a production schedule. A single case study is used to illustrate the development and evaluation of a product wheel design.
Findings
The results show that the product wheel concept does achieve the aim of grouping similar products in the production schedule, and, as such, can be used to improve the production planning process through the reduction of the number of time-intensive changeovers without sacrificing product availability to meet customer demand. The product wheel, however, is not a mathematical optimization technique; but is instead a heuristic technique which requires the use of judgment and experience to achieve an optimal design.
Originality/value
A theoretical contribution to the study of mix flexibility has been made, where the application of the product wheel construct presents a novel approach to the study of operational mix flexibility achievement, via the sequencing of products on shared manufacturing resources.
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Rolando Quintana and Mark T. Leung
Most setup management techniques associated with electronic assembly operations focus on component similarity in grouping boards for batch processing. These process planning…
Abstract
Most setup management techniques associated with electronic assembly operations focus on component similarity in grouping boards for batch processing. These process planning techniques often minimize setup times. On the contrary, grouping with respect to component geometry and frequency has been proved to further minimize assembly time. Thus, we propose the Placement Location Metric (PLM) algorithm to recognize and measure the similarity between printed circuit board (PCB) patterns. Grouping PCBs based on the geometric and frequency patterns of components in boards will form clusters of locations and, if these clusters are common between boards, similarity among layouts can be recognized. Hence, placement time will decrease if boards are grouped together with respect to the geometric similarity because the machine head will travel less. Given these notions, this study develops a new technique to group PCBs based on the essences of both component commonality and the PLM. The proposed pattern recognition method in conjunction with the Improved Group Setup (IGS) technique can be viewed as an extended enhancement to the existing Group Setup (GS) technique, which groups PCBs solely according to component similarity. Our analysis indicates that the IGS performs relatively well with respect to an array of existing setup management strategies. Experimental results also show that the IGS produces a better makespan than its counterparts over a low range of machine changeover times. These results are especially important to operations that need to manufacture quickly batches of relatively standardized products in moderate to larger volumes or in flexible cell environments. Moreover, the study provides justification to adopt different group management paradigms by electronic suppliers under a variety of processing conditions.
Jagdeep Singh, Harwinder Singh and Inderdeep Singh
The purpose of this paper is to uncover the significance of SMED in manufacturing environments.
Abstract
Purpose
The purpose of this paper is to uncover the significance of SMED in manufacturing environments.
Design/methodology/approach
The paper gives setup instructions and guidelines to prepare the standardized setup procedure without ignoring actual constraints in production environment. It uses a case study in a small-scale manufacturing unit of northern India to generate an integrated setup reduction approach, utilizing Single Minute Exchange of Die (SMED)-based industrial engineering tools to achieve faster setups. It describes the feasibility of quick changeovers in small enterprises based on an “SMED” approach. Finally, the paper carries out empirical analysis of the financial/non-financial benefits incurred from setup reductions.
Findings
Setup activities are a vital part of the production lead time of any product and so affect overall product cost. Industrial engineering techniques have been used to analyze the existing procedure of setups. A SMED approach can help eliminate unwanted activities, externalize the internal activities, if possible, and reduce them by simplification or standardization.
Originality/value
The paper demonstrates the practical application of SMED showing how it can bring real breakthroughs in reducing setup time in small-scale manufacturing.
Details