Enhancement of sigma level in the manufacturing of furnace nozzle through DMAIC approach of Six Sigma: a case study

The performance improvement analysis using Six Sigma DMAIC methodology: A case study on Indian manufacturing company

The six-sigma methodology has been adopted by the industry as a business management tool to improve operational capabilities and reduce defects in any process. This study aims to present a case study on the implementation of the Six-Sigma DMAIC methodology with the purpose to reduce the rejection rate of rubber weather strips manufactured by XYZ Ltd. (name changed) situated in Gurugram, India. Weather strips are used in all four doors of cars for noise reduction, waterproofing, dust proofing, soundproofing, windproofing, and for improving air conditioning cooling, and heating effects. The overall rejection rate of both front and rear door rubber weather strips was 5.5% which was causing a huge loss to the company. The average rejection rate of rubber weather strips per day reduced from 5.5% to 3.08%. After implementing the Six-Sigma project findings the rejection was reduced from 153 pieces to 68 pieces helped the industry in saving the cost of a compound by Rs. 15,249 per month. The sigma level improved from 3.9 to 4.45 within three months with the implementation of one Six-Sigma project solution. The company was highly concerned about reducing the high rejection rate of rubber weather strips and decided to deploy Six Sigma DMAIC as a quality improvement tool. The industry was keen to reduce this high rejection rate to 2% and this target was materialized with the application of the Six-Sigma DMAIC methodology. The novelty of this study is to analyze performance improvement considering the Six Sigma DMAIC methodology to reduce the rejection rate of rubber weather strip manufacturing companies.

The Development of an Excellence Model Integrating the Shingo Model and Sustainability

Companies are continuously looking to improve their production systems using excellence models, with lean thinking, the Shingo model, six sigma and lean six sigma being the most comprehensive and applied. It is expected that the initial focus for the survival of companies is their economic profitability, but when economic needs are met, the next step is to achieve operational excellence. For this, in addition to economic objectives, it is necessary to include social and environmental objectives, i.e., the other two pillars of sustainability. This study aims to propose a conceptual model identifying the tools that can help achieve the desired results in the three pillars of sustainability aligned with operational excellence. The design of the conceptual model was based on a bibliometric analysis of the literature that relates the concepts of lean thinking, six sigma, lean six sigma and the Shingo model. The Web of Science was the platform selected for the collection of data, and the timeframe considered was 2010 to 2021. A total of 125 articles were analyzed using the VosViewer software, through which it was possible to analyze different topics of study related to the literature. The bibliometric analysis allowed for the identification of the temporal distribution of publications, the categorization of topics, different areas of application and the importance of the tools used in different practical cases. This study points out that companies have at their disposal several tools to achieve economic objectives. On the other hand, there is a set of more restricted tools that are used to meet the objectives of the social and environmental pillars. Future research should focus on identifying tools that meet social and environmental goals in order to strengthen these pillars that are essential for operational excellence and for the sustainability of companies.

Optimising process and product performance in complex systems: a study in the automotive industry

Purpose

This study responds to calls from industry and the literature to cope with the enormous challenges faced by companies operating in competitive business sectors. The main objective of this paper is to investigate how managers can optimise product quality and process efficiency of complex systems.

Design/methodology/approach

In this paper, a design of experiments (DoE) method was used to improve the development of complex products and manufacturing processes in the industry of automotive audio components. To identify the optimal combination that minimises quality problems occurring with subwoofer speakers in the marketing, this study proposed a full Factorial experiment 24 with three replications in a single block summarised in an analysis of the interaction among the factors.

Findings

The research findings revealed the factors and levels regarding both the product development and manufacturing processes that significantly impact the quality and reliability performance of the subwoofer speaker analysed. The findings from the article allowed the company to prioritise internal improvements to enhance product quality and process efficiency. Other automotive firms will benefit from the research findings obtained.

Practical implications

From a managerial perspective, this research presented the DoE methodology as a real opportunity to deal with the inherent complexity of the manufacturing process in the automotive audio components sector. This research assist managers with insights into how they can improve the quality performance in production systems and in the market.

Originality/value

This study is an original contribution to the advance of theory and empirical implementation of DoE in competitive industrial sectors.

A Six-Sigma DMAIC Approach to Improve the Sales Process of a Technology Start-Up

Despite the adoption of Six-Sigma in different service sectors, its application in the Sales function of a Technology-based Start-up has not been explored. This paper deploys an action research-based study methodology and conducts a thorough analysis of a Technology Start-up company in Indonesia, using Six-Sigma principles and the Define-Measure-Analyse-Improve-Control (DMAIC) approach. Statistical validation of the causes of problems helped to formulate a strategy that may have otherwise not been possible. The results of the study and proposed solutions confirm the potential benefits of adopting Six-Sigma in the Sales function of technology start-ups to reduce, particularly, customer waiting time. The novelty of this research lies in the fact that it applies Six-Sigma in a transactional process such as sales, which earlier studies have not explored in depth. This paper can be employed as a reference for organisations to undertake and guide specific process improvement projects similar to the one presented.

Critical review of literature on Lean Six Sigma methodology

Purpose

This paper aims to develop an initial understanding of the Lean Six Sigma methodology since its inception and examine the few Lean Six Sigma dimensions as a research domain through a critical review of the literature.

Design/methodology/approach

The paper is structured in two-part. The first part of the paper attempts to dwell on the evolution of the Lean Philosophy and Six Sigma methodology individually and the emergence of Lean Six Sigma methodology, covered under the Lean Six Sigma: a historical outline section. The second part of the study examines the dimensions associated with Lean Six Sigma such as frameworks, critical success factors, critical failure factors, type of industry, performance metric, year, publisher and journal, based on a total of 223 articles published in 72 reputed journals from the year 2000 to 2019 as a literature review.

Findings

The adoption of Lean Six Sigma, as a continuous improvement methodology, has grown enormously in the manufacturing and few service sectors such as health care and higher education during the past decade. The study revealed that researchers came out with conceptual frameworks for the implementation of Lean Six Sigma, whereas the validation through case studies seems to be lacking. The integration of Lean Six Sigma and other approaches with a focus on sustainability and the environment has emerged as a research field. A few of the most common critical success and failure factors were identified from the articles studied during the study.

Research limitations/implications

This paper may not have included some of the studies due to the inaccessibility and selection criteria followed for the study.

Originality/value

This paper will provide an initial introduction on Lean, Six Sigma and Lean Six Sigma and research insights Lean Six Sigma to beginners such as students, researchers and entry-level professionals.

Application of Lean Six Sigma framework for improving manufacturing efficiency: a case study in Indian context

Purpose

This study aims to utilize DMAIC methodology along with value stream mapping and other Lean Six Sigma tools in a major automobile light manufacturing industry to reduce defect rates and increase production capacity in their manufacturing line. The study also proposes a modified framework based on lean principles and FlexSim to identify and reduce waste in the selected industry.

Design/methodology/approach

A Lean Six Sigma modified framework has been deployed with DMAIC to reduce the defect rate and increase the production rate. Various tools like value stream mapping, brainstorming, Pareto charts, 5S, kanban, etc. have been used at different phases of DMAIC targeting wastes and inventory in the production line. Also, a simulation model has been utilized for the automobile light manufacturing industry to improve the machine utilization time with varying batch sizes.

Findings

The results of the study indicated a 53% reduction in defect rates. Thus, there would be an expected improvement in sigma value from 3.78 to 3.89 and a reduction in defects per million opportunities (DPMO) from 11,244 to 8,493. Additionally, simulation model using FlexSim was developed, and the optimum ordering batch size of raw material was obtained. It was also analyzed that idle time for various stations could be reduced by up to 30%.

Practical implications

The utilized framework helps identify defects for managers to increase production efficiency. The workers, operators and supervisors on the production line also need to be trained regularly for identifying the areas of improvement.

Originality/value

The modified Lean Six Sigma framework used in this study includes FlexSim simulation to make the framework robust, which has not been used with LSS tools in the literature studied. Also, the LSS finds very less application in the manufacturing domain, considering which this study tends to add value in existing literature taking a case of an automobile light manufacturing industry.

Fuzzy assessment analysis and key improvements to a production system

Purpose

The framework of Six Sigma Define-Measure-Analyze-Improve-Control was applied in this study, and various tools and techniques were used at different stages to implement lean measures to ensure quality. The purpose of this paper is to develop a decision-making framework that assesses key quality performance to ensure that practitioners improve quality and control by modeling and optimizing production processes.

Design/methodology/approach

A model of a quality performance index system was established. The weights of factors and sub-factors, which were estimated using an FAHP, were used as a reference for the decision maker under fuzzy uncertainly to make a decision, and thus, results present the bottlenecks in processes. Furthermore, any other factors that may affect the key process bottlenecks must be considered. The critical to quality characteristics were determined, and factor levels were set. The interaction between the factors was analyzed, their significance was studied using the Design of experiments and the parameters were predicted. Finally, quality improvement decisions were made through failure mode and effects analysis.

Findings

The implementation results of this research prove that the proposed model could successfully determine the key processes and focus on the improvement of critical quality factors under limited resources.

Originality/value

This study establishes a set of performance appraisal methods for production systems, which can be used for improving productivity and quality.

Application of Six Sigma DMAIC methodology to reduce the defects in a telecommunication cabinet door manufacturing process

Purpose

The purpose of this paper is to apply the Six Sigma DMAIC methodology in order to reduce the rejections experienced in the manufacturing of the doors belonging to a telecommunication cabinet.

Design/methodology/approach

The process involved joining of sheet metal and hinge using welding operations with the help of a fixture. The methodology used is the structured DMAIC method in order to identify the root cause for the rejections and solve it.

Findings

The paper provides insights about the identification of the root cause for the defects and the solution to overcome it, and also the benefits that were obtained as a result of the application of the solution.

Research limitations/implications

This methodology has been applied to the variation observed in the dimensions of a particular component to be welded with a main part. This approach can be used to find such dimensional variations.

Practical implications

This study has been successfully carried out in a medium-scale industry which has total quality management in practice.

Originality/value

Six Sigma DMAIC was necessary for the identification and reduction of the defects which arose in the sheet metal and welding operations, and had to be resolved in order to increase the bottom-line.

Six Sigma 4.0

Der vorliegende Beitrag vergleicht Six-Sigma- und Data-Mining-Methoden im Hinblick auf das Null-Fehler-Management in Produktionsprozessen. Darauf aufbauend wird ein Six-Sigma-4.0-Prozessmodell abgeleitet, das die Stärken beider Ansätze vereint und somit einen Handlungsleitfaden für Verbesserungsprojekte im Rahmen der Indus-trie 4.0 bereitstellt. Das vorgestellte Six-Sigma-4.0-Modell wird im Zuge eines Verbesserungsprojekts im Bereich der Elektronikproduktion validiert.

Critical review and analysis of measuring the success of Six Sigma implementation in manufacturing sector

Purpose

The purpose of this paper is to capture the status of implementation of Six Sigma in various manufacturing industries and also examine the success of the Six Sigma by using different performance indicators.

Design/methodology/approach

The methodology of critical review involves the selection and classification of 112 research articles on the implementation of Six Sigma in different manufacturing industries. The selected articles are categorized by the following: articles distribution based on the year of publication, publication database, various journals, contribution of authors, continent, scale of industry, implemented approaches, focused industry, tools and techniques used in phases of Six Sigma methodology, and performance indicators used in Six Sigma implementation. Then after, future scopes of research opportunities are derived based on significant findings.

Findings

The literature revealed that: Very few work was undertaken on the implementation of Six Sigma in various manufacturing industries like ceramic, paper, gems and jewelry, cement, furniture, stone, fertilizer, forging, paper and surface treatment industries. Most of the researchers have considered very few performance indicators to identify the improvement after Six Sigma implementation. But, there is no clue regarding overall improvement in different perspectives after the implementation of Six Sigma. The financial indicators, personnel indicators, process indicators and customer indicators are useful to measure the overall improvement after the implementation of Six Sigma in the manufacturing sector.

Research limitations/implications

The study was carried out on the implementation of Six Sigma methodology in various manufacturing industries, and various performance indicators were identified while implementing the Six Sigma methodology. Case studies pertaining to service industries were not covered here.

Originality/value

Very little research has been carried out to measure the overall success of implementing Six Sigma methodology in manufacturing industries. This paper will provide value to students, researchers and practitioners of Six Sigma by providing insight into the implementation of Six Sigma in manufacturing industries.