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Article
Publication date: 23 April 2021

Ashkan Ayough, Farbod Farhadi and Mostafa Zandieh

This paper aims to unfold the role that job rotation plays in a lean cell. Unlike many studies, the authors consider heterogeneous operators with dynamic performance factor that…

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Abstract

Purpose

This paper aims to unfold the role that job rotation plays in a lean cell. Unlike many studies, the authors consider heterogeneous operators with dynamic performance factor that is impacted by the assignment and scheduling decisions. The purpose is to derive an understanding of the underlying effects of job rotations on performance metrics in a lean cell. The authors use an optimization framework and an experimental design methodology for sensitivity analysis of the input parameters.

Design/methodology/approach

The approach is an integration of three stages. The authors propose a set-based optimization model that considers human behavior parameters. They also solve the problem with two meta-heuristic algorithms and an efficient local search algorithm. Further, the authors run a post-optimality analysis by conducting a design of experiments using the response surface methodology (RSM).

Findings

The results of the optimization model reveal that the job rotation schedules and the human cognitive metrics influence the performance of the lean cell. The results of the sensitivity analysis further show that the objective function and the job rotation frequencies are highly sensitive to the other input parameters. Based on the findings from the RSM, the authors derive general rules for the job rotations in a lean cell given the ranges in other input variables.

Originality/value

The authors integrate the job rotation scheduling model with human behavioral and cognitive parameters and formulate the problem in a lean cell for the first time in the literature. In addition, they use the RSM for the first time in this context and offer a post-optimality analysis that reveals important information about the impact of the job rotations on the performance of operators and the entire working cell.

Details

Assembly Automation, vol. 41 no. 2
Type: Research Article
ISSN: 0144-5154

Keywords

Article
Publication date: 2 March 2015

Patrick Pujo, Ilham El Khabous and Fouzia Ounnar

The aim of this research is to discuss the benefits of U-shaped layout for production cell operating in variable takt time. Different experiments were conducted using benchmarks…

Abstract

Purpose

The aim of this research is to discuss the benefits of U-shaped layout for production cell operating in variable takt time. Different experiments were conducted using benchmarks to highlight the performance gap between a linear cell and a U-Cell.

Design/methodology/approach

The implementation of the production cell, either in a U-shaped or in a straight line layout, is optimized through linear programming based on the number of operators. The two corresponding programs, in Mosel language, use the same approach to not introduce bias in the comparison of results. The study used the authors’ own datasets and other well-known academic benchmarks.

Findings

A comparison was conducted between the obtained takt times, with equivalent operating conditions, in both U-Cell and linear cell. A significant increase of the production rate was observed. This increase has often exceeded 10 per cent, reaching 32 per cent. All the experiments show that, with the same number of operators, a cell in a U-shaped layout is always at least as efficient, in terms of attainable production rates, than an equivalent linear cell. Ninety-six per cent of the studied cases give an improvement of production rate. Moreover, the dispersion of the U-Cell results is weaker, which suggests that the U-shaped layout gives better performances in more robust manner.

Research limitations/implications

Results were obtained through a study of various academic benchmarks. The results must be validated on industrial situations.

Practical implications

This paper will be very useful for researchers and practitioners to understand lean implementations and their derived benefits. This paper will allow them to evaluate and analyze the expected benefits of the implementation of the production cell in the U-shaped layout (operating in variable takt time).

Originality/value

U-Cells constitute an appropriate solution for a layout of any kind of production cells with a variable structure (variability of the number of operators, of the organization of the cell, of the takt time […]). When facing a significant variation in the demand, the response consists of adjusting the number of operators assigned to the cell. This study jointly addresses the problem of the U-shaped layout and the operation in variable takt time.

Details

International Journal of Lean Six Sigma, vol. 6 no. 1
Type: Research Article
ISSN: 2040-4166

Keywords

Book part
Publication date: 20 November 2023

Esmir Demaj and Denis Mehillaj

Lean manufacturing, a philosophy that revolutionized the manufacturing industry, is often linked to the Toyota Production System (TPS). At the core of a lean company, one can…

Abstract

Lean manufacturing, a philosophy that revolutionized the manufacturing industry, is often linked to the Toyota Production System (TPS). At the core of a lean company, one can observe proper implementation of lean manufacturing tools and practices such as just-in-time, work teams, cellular manufacturing, lean layout, etc. The goal of lean production is to minimize the waste producing activities while offering the same or enhanced quality to customers.

The aim of this research is to investigate the implementation degree of lean manufacturing and its tools and practices focusing on the case of an SME in Albania as a concrete example. Higher attention is given to some of the pillars of lean manufacturing such as just-in-time and cellular manufacturing.

In this case study, researchers observed a variety of features of lean production. Just-in-time was implemented to a certain extent and cellular manufacturing at a more surprising level, which was facilitated especially by the U-shaped facility layout designs observed during the site visits. The value stream mapping showed a proper group technology in place and the management displayed signs of engagement and future advancement desire regarding this philosophy.

Details

Digitalization, Sustainable Development, and Industry 5.0
Type: Book
ISBN: 978-1-83753-191-2

Keywords

Article
Publication date: 12 August 2021

Juliano Endrigo Sordan, Pedro Carlos Oprime, Marcio Lopes Pimenta, Franco Lombardi and Paolo Chiabert

The present paper aims to demonstrate the potential of integration between industrial robotics and Lean Manufacturing (LM) approach to increase the efficiency of an assembly line.

Abstract

Purpose

The present paper aims to demonstrate the potential of integration between industrial robotics and Lean Manufacturing (LM) approach to increase the efficiency of an assembly line.

Design/methodology/approach

Based on a case study performed in an Italian company, this paper reports a comparative analysis of the results produced on a line balancing study involving a semi-automated production line, aided by an industrial robot.

Findings

The results suggest the possibility of implementing industrial robotics in line balancing studies highlighting efficiency gains and idle reduction. Further, it also addresses some concepts directly related to industry 4.0, such as collaborative robotics, artificial intelligence, and lean automation.

Practical implications

Line balancing studies may include advanced robotics in order to extend traditional lean practices toward Digital LM.

Originality/value

This study adds contributions to the operational excellence literature, demonstrating the symbiosis between industrial robotics and LM practices.

Details

The TQM Journal, vol. 34 no. 5
Type: Research Article
ISSN: 1754-2731

Keywords

Article
Publication date: 11 May 2015

Teng-Kuan Wang, Taho Yang, Chih-Yao Yang and Felix T.S. Chan

The purpose of this paper is to use lean principles and simulation optimization on solving a combined hospital emergency department (ED) layout design and staff assignment…

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Abstract

Purpose

The purpose of this paper is to use lean principles and simulation optimization on solving a combined hospital emergency department (ED) layout design and staff assignment problem.

Design/methodology/approach

This study is based on value stream mapping for the design and analysis of the ED. Subsequently, the authors investigate cellular manufacturing design, which addresses the decisions of continuous steps in a cell simultaneously and considers the optimal staff assignment. A simulation based on the case study is used for these methodologies. Simulation optimization is then used to optimize the staff assignments, minimize the waiting time and maximize the service level.

Findings

The linear layout outperformed in both waiting time and service level. The patients’ average waiting time is reduced from 78 to 38 minutes. The service level increased from 54.86 to 88.55 percent. Moreover, the number of nurses was reduced from nine to six.

Research limitations/implications

First, the tests for model accuracy were performed using the actual arrival rate; however, seasonal variation should be reflected. Second, the staffing levels varied were not tracked. Third, the accuracy of individual patient treatment paths can be dynamic. Fourth, the 25 percent of delays in transferring a patient to an inpatient bed will be discussed in future studies.

Practical implications

A practical case is adopted for empirical illustrations.

Originality/value

The proposed methodology innovatively solved a practical application and the results are promising.

Details

Industrial Management & Data Systems, vol. 115 no. 4
Type: Research Article
ISSN: 0263-5577

Keywords

Article
Publication date: 22 July 2021

Xiaodie Pu, Meng Chen, Zhao Cai, Alain Yee-Loong Chong and Kim Hua Tan

This study aims to examine the impact of lean manufacturing (LM) on the financial performance of companies affected by emergency situations. It additionally explores the role of…

Abstract

Purpose

This study aims to examine the impact of lean manufacturing (LM) on the financial performance of companies affected by emergency situations. It additionally explores the role of advanced manufacturing technologies (AMTs) in complementing LM to enhance financial performance in emergency and non-emergency situations.

Design/methodology/approach

Both survey and archival data were collected from 219 manufacturing companies in China. With longitudinal data collected before and after an emergency situation (i.e. Typhoon Rumbia), regression analysis was conducted to investigate the effects of LM and AMTs on financial performance in different contexts.

Findings

Our results reveal an inverted U-shaped relationship between LM and financial performance in the context of emergency. We also found that AMTs exerted a positive moderation effect on the inverted U-shaped relationship, indicating high levels of AMTs that mitigated the inefficiency of LM in coping with supply chain emergencies.

Research limitations/implications

Through simultaneous investigation of LM and AMTs as bundles of practices and their fit with different contexts, this study takes a systems approach to fit that advances the application of contingency theory in the Operations Management literature to more complex patterns of fit.

Originality/value

This study illuminates how AMTs support LM practices in facilitating organizational performance in different contexts. Specifically, this study unravels the interaction mechanisms between AMTs and LM in influencing financial performance in emergency and non-emergency situations.

Details

International Journal of Operations & Production Management, vol. 41 no. 9
Type: Research Article
ISSN: 0144-3577

Keywords

Article
Publication date: 15 March 2018

Cem Savas Aydin, Senim Ozgurler, Mehmet Bulent Durmusoglu and Mesut Ozgurler

This paper aims to present a multi-response robust design (RD) optimization approach for U-shaped assembly cells (ACs) with multi-functional walking-workers by using operational…

Abstract

Purpose

This paper aims to present a multi-response robust design (RD) optimization approach for U-shaped assembly cells (ACs) with multi-functional walking-workers by using operational design (OD) factors in a simulation setting. The proposed methodology incorporated the design factors related to the operation of ACs into an RD framework. Utilization of OD factors provided a practical design approach for ACs addressing system robustness without modifying the cell structure.

Design/methodology/approach

Taguchi’s design philosophy and response surface meta-models have been combined for robust simulation optimization (SO). Multiple performance measures have been considered for the study and concurrently optimized by using a multi-response optimization (MRO) approach. Simulation setting provided flexibility in experimental design selection and facilitated experiments by avoiding cost and time constraints in real-world experiments.

Findings

The present approach is illustrated through RD of an AC for performance measures: average throughput time, average WIP inventory and cycle time. Findings are in line with expectations that a significant reduction in performance variability is attainable by trading-off optimality for robustness. Reductions in expected performance (optimality) values are negligible in comparison to reductions in performance variability (robustness).

Practical implications

ACs designed for robustness are more likely to meet design objectives once they are implemented, preventing changes or roll-backs. Successful implementations serve as examples to shop-floor personnel alleviating issues such as operator/supervisor resistance and scepticism, encouraging participation and facilitating teamwork.

Originality/value

ACs include many activities related to cell operation which can be used for performance optimization. The proposed framework is a realistic design approach using OD factors and considering system stochasticity in terms of noise factors for RD optimization through simulation. To the best of the authors’ knowledge, it is the first time a multi-response RD optimization approach for U-shaped manual ACs with multi-functional walking-workers using factors related to AC operation is proposed.

Details

Assembly Automation, vol. 38 no. 4
Type: Research Article
ISSN: 0144-5154

Keywords

Article
Publication date: 1 March 2003

Antonio C. Caputo and Pacifico M. Pelagagge

Describes the reengineering of a production line for household heating tubular radiators, assuming as a reference scenario the facility of one of the leading Italian…

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Abstract

Describes the reengineering of a production line for household heating tubular radiators, assuming as a reference scenario the facility of one of the leading Italian manufacturers. After a preliminary characterization of products and manufacturing process, a thorough analysis of the production system has been carried out in order to highlight current problems and improvement strategies in the light of lean manufacturing concepts. Subsequently, suggests some corrective actions and also assesses their expected effectiveness in economic terms. In particular, improvement possibilities have been found in the areas of internal logistics through streamlining of materials flow and layout modifications, as well as process quality increase. Reengineering activities are especially aimed towards layout optimization mainly by resorting to a U‐shaped cell‐based architecture. Further, the reduction of rework percentage during the assembly phase has been pursued by properly modifying the operations sequence and through integration of a new automated testing station in the production line.

Details

Integrated Manufacturing Systems, vol. 14 no. 2
Type: Research Article
ISSN: 0957-6061

Keywords

Article
Publication date: 13 April 2023

Evangelos Psomas, Efthalia Keramida, Nancy Bouranta and Dimitrios Kafetzopoulos

In times of strong global competition and worldwide economic downturn, there is an imperative need for public services organizations to reform and improve their quality. These…

Abstract

Purpose

In times of strong global competition and worldwide economic downturn, there is an imperative need for public services organizations to reform and improve their quality. These organizations can base their improvement efforts on Lean philosophy. The purpose of this study is to assess the employees’ perceived degree of adoption of Lean principles by public services organizations in Greece. Determining the differences in the perceptions of groups of employees with regard to the adoption of Lean principles by public organizations is also an aim of the study.

Design/methodology/approach

A questionnaire survey was published online, inviting employees of Greek public services organizations to assess the degree of Lean adoption by their organizations, specified on the basis of general principles. A total of 1,022 employees completed the structured questionnaire. Descriptive statistics were applied to assess the degree of adoption of Lean principles by public organizations. The nonparametric Mann–Whitney U Test and Kruskal–Wallis Test were also applied to determine whether there are statistically significant differences in the perceptions of groups of employees with regard to the adoption of Lean principles by public organizations.

Findings

According to the perceptions of employees, Greek public organizations adopt Lean principles to a high extent. However, there is room for further improvement in the degree to which Lean is adopted. Statistically significant differences are observed in the perceptions of groups of employees from different sized organizations, hierarchical levels, skill sets and service subsectors, with regard to the degree of adoption of Lean principles by their organizations.

Research limitations/implications

The employees of the public sector who were invited to respond to the survey through social media, the subjective nature of the data collected and the fact that this is a country-specific study constitute the main limitations of the present study, based on which future studies can be designed.

Practical implications

By determining the strong and weak points of the adoption of Lean principles by Greek public services organizations, suitable managerial initiatives can be undertaken by these organizations to fully adopt Lean, eliminate waste and enhance quality management.

Social implications

Understanding and improving the current status of the adoption of Lean principles by Greek public organizations will influence the services provided to the citizens in terms of time, quality and delivery.

Originality/value

To the best of the authors’ knowledge, this is the first study which provides insights, based on employees’ perceptions, into the adoption of Lean by the public services sector.

Details

International Journal of Lean Six Sigma, vol. 14 no. 7
Type: Research Article
ISSN: 2040-4166

Keywords

Article
Publication date: 1 October 2006

Andrew Lee‐Mortimer

Aims to detail the ongoing implementation of lean manufacturing at a UK‐based electronic product‐manufacturing operation.

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Abstract

Purpose

Aims to detail the ongoing implementation of lean manufacturing at a UK‐based electronic product‐manufacturing operation.

Design/methodology/approach

Describes how and why a manufacturing operation, which had already seen major improvements that had made it a highly regarded plant, is adopting lean manufacturing as part of a manufacturing survival strategy. It also looks at some of the main Lean projects undertaken, the major benefits gained and the key lesson learned.

Findings

While the operation's highly effective continuous improvement programme had delivered a major culture change along with significant OEE and quality improvements, the introduction of lean manufacturing highlighted that this had been achieved at the cost of creating a number of “islands of excellence”; resulting in high levels of WIP and long lead times. The implementation of lean manufacturing is now enabling this electronic products manufacturer to build on its excellent foundation of continuous improvement, and start the process of moving away from batch and queue to creating flow through the whole plant; reducing WIP and lead time, and improving productivity, without compromising previous gains.

Originality/value

Brings to the attention of managers how it often takes the wider focus offered by lean manufacturing to discover the hidden waste that can reside even in operations that appear to be very effective. Confirms the importance of moving from a batch and queue mentality to process flow, and the productivity benefits that can be gained, but also highlights that even well‐organised businesses are liable to suffer pain when implementing lean, especially with respect to introducing flow and eliminating WIP, which has to be worked through.

Details

Assembly Automation, vol. 26 no. 4
Type: Research Article
ISSN: 0144-5154

Keywords

1 – 10 of 116