International Journal of Six Sigma and Competitive Advantage (8 papers in press)

Regular Issues

• Improvement of process capability analysis through Six Sigma methodology: a case study in the capacitor manufacturing industry  
  by Ravi Shankar Raman, Yadavalli Basavaraj, Nidhi Singh, Mahender Singh Kaswan, Varun Singhal 
  Abstract: Six Sigma implies that process improvement has been an emerging subject among various researchers and industrialists over recent decades. Very few studies have been conducted about the beneficial uses of Six Sigma in the capacitor industry. The industry has embraced the Six Sigma methodology as a business management tool to enhance operational capabilities and lower process faults. The objective of this research is to provide a case study on the application of the Six-Sigma DMAIC technique to reduce the rejection rate of out of tolerance (OTR) defects during pressing operation and enhance the process capability index by optimising the parameters in the capacitor manufacturing industry. This paper focuses on the projects selection and the various steps to be followed during the Six Sigma methodology. During the research, various Six Sigma tools and techniques were successfully applied. The consequences of the literature review show that many industries are unaware of Six Sigma and do not have the resources to fill the required gap. It was found that the application of Taguchis orthogonal array with Six Sigma was not very familiar among industries for improving process capability. After analysing all the parameters, a substantial improvement in the rejection of OTR and improvement in process capability Cp and Cpk values was found.
  Keywords: Six Sigma; Taguchi method; orthogonal array; analysis of variance; ANOVA.
  DOI: 10.1504/IJSSCA.2024.10066149
   
  
• Scrap reduction in confectionery plant through Lean Six Sigma  
  by Aravindh Kumaran Lekshmana Perumal, Sivakumar Kirupanandan, Gangesh Palani Gopinath 
  Abstract: The application of Lean Six Sigma (LSS) in scrap reduction of confectionery plants is demonstrated with a case study in this paper by identifying the possibilities of reducing scrap thereby improving efficiency of the continuous process. This study adopted a cross-sectional study of a complete cycle of value stream mapping (VSM) Define Measure Analyse Improve and Control (DMAIC), the LSS approach by observing the plant over months. This study was conducted in a unique production company to explore the scrap reduction in manufacturing chocolates using LSS approach. The outcome of the study demonstrates that the scrap has been reduced from 30 kg to 2.5 kg led to significant savings for the company through obtaining correct machinery setting by using predictive analytics. The results of the study present the major contributors and success contributors that future researchers and consultants can use to eliminate scrap specifically in the continuous process industry.
  Keywords: Lean Six Sigma; LSS; value stream mapping; VSM; DMAIC; scrap reduction; confectionery plant; food processing industry.
  DOI: 10.1504/IJSSCA.2024.10067905
   
  
• AI-driven quality control techniques in manufacturing processes to enhance Six Sigma approach  
  by Nadia Hoggas, Ouassila Hioual, Amel Hebboul 
  Abstract: Six Sigma is a business strategy focused on reducing defects and variations in products and processes, thereby enhancing quality. The rise of Industry 4.0 technologies has increased data volumes in manufacturing, creating challenges for integrating Six Sigma methodologies. To adapt, we propose an enhanced Six Sigma approach incorporating AI technologies to optimise performance in this new landscape. This paper proposes a new methodology, the 5I method (identify, inspect, investigate, implement, improve) combines statistical methods and predictive analysis using machine learning, aiming to achieve data-driven predictive quality. To develop a robust model for detecting all types of steel plate defects, we propose a hybrid statistical sampling algorithm that combines the synthetic minority over-sampling technique (SMOTE) and edited nearest neighbour (ENN). Additionally, we applied a universal deep neural network (DNN) as a classifier of defects, achieving an impressive prediction accuracy of 99.05%, surpassing other machine learning algorithms.
  Keywords: Six Sigma; Industry 4.0; Quality 4.0; 5I; classification; synthetic minority over-sampling technique; SMOTE; edited nearest neighbour; ENN; deep neural network; DNN.
  DOI: 10.1504/IJSSCA.2024.10068753
   
  
• The impact of total quality management practices on competitive advantage  
  by Tryson Yangailo 
  Abstract: Total quality management (TQM) is widely regarded as a means of achieving competitive advantage (CA), but lacks a robust theoretical underpinning. This study examines this claim in the railway sector, an under-researched area. It evaluates the impact of TQM on CA in the Tanzania Zambia Railway Authority (TAZARA). One hundred fifty one out of 200 managers surveyed responded. Correlation and regression analysis revealed a significant positive relationship between TQM practices and CA. In particular, quality results and process management have a positive impact on CA. However, aspects such as customer focus, employee involvement, education, training and top management commitment show no significant impact. The study calls for further research into the effects of TQM in railways and recommends government intervention to rejuvenate the sector. These include regulatory measures to shift freight to rail, infrastructure investment and the creation of dedicated regulatory or development agencies.
  Keywords: total quality management; TQM practices; competitive advantage; CA; railway sector.
  DOI: 10.1504/IJSSCA.2024.10065880
   
  
• Optimisation of defects using quality circle approach by QCFI India: a manufacturing case study of heat exchanger for automobiles  
  by Adapa Sai Krishna, Basant Singh Sikarwar, Rakesh Kumar Phanden 
  Abstract: Rapid changes in environmental weather conditions make air conditioning (AC) the basic need in automobiles to provide thermal comfort to passengers. AC in automobiles is a complex system consisting of heat exchangers (HEs) that play a crucial role in exchanging heat between two mediums. The manufacturing of HEs is a complex process, and during this process, many defects were generated that decreased efficiency and increased scrap cost. The main objective of the present research is to analyse and optimise these defects, a task that requires a deep understanding of the manufacturing process and the factors that contribute to defects. The approach suggested by QCFI India, and the use of Six Sigma tools has been instrumental in achieving this goal. The defects are typically generated at the point of heat applications like brazing. The minimum rejection parts per million (PPM) of the pinhole and inner leak defect was achieved by optimal setting of separator height between 21.07 mm to 21.17 mm and refluxing with potassium-aluminiflorate flux. Finally, after implementing optimal settings with several improvement configurations, the significant defects were reduced to around 85.4%.
  Keywords: manufacturing defects; flux; cause and effect diagram; QCFI method; Six Sigma; heat exchangers; PPM; quality control; India.
  DOI: 10.1504/IJSSCA.2024.10067679
   
  
• Efficacy of Lean Six Sigma in forensic investigation: a conceptual analysis  
  by Tejasvi Pandey, Anindita Malik, Sweta Sagarika Das, Mahipal Singh 
  Abstract: Forensic science is often facing issues like delays in results, quality, accuracy, and reliability in outcomes. It is of foremost significance to implement approaches that create synchronisation between quality and real solutions to societal problems. The number of case pendency's are increasing in India due to various reasons such as improper evidence handling, packaging and examination, lack of training, etc. Probably it is expected to increase more soon if this trend remains. Lean Six Sigma (LSS) is one of the emerging approaches that can enhance the efficiency of methodology and the outcome in forensics by using the DMAIC roadmap. The outcome of this work exhibits the identification of challenges and plans a strategy to minimise the errors in the procedures of forensic testing. LSS identifies opportunities for improvement in providing an excellent platform to maintain integrity and authenticity among cases in forensic sciences.
  Keywords: Lean Six Sigma; LSS; forensic science; DMAIC; process performance.
  DOI: 10.1504/IJSSCA.2024.10067547
   
  
• Changeover time reduction in TV assembly line using Lean Six Sigma: a case study  
  by Omayma A. Nada, Mohamed A. El-Dardiry, Zainab E. El-Dardiry 
  Abstract: In manufacturing systems dealing with relatively high product mix in small batches, changeover time is one of the most critical issues that could significantly affect the responsiveness and efficiency of such production lines. Accordingly, this paper demonstrates a case study concerned with employing the Lean Six Sigma (LSS) to reduce the changeover time in a company's TV assembly line that produces different variety of models in relatively small batches to satisfy the market needs. This paper customised the value stream mapping tool such that it can be employed in analysing the changeover process itself to identify and minimise the non-value-added activities within it. The LSS implementation has resulted in identifying the dominant causes for extended changeover time and accordingly improvement countermeasures have been introduced. These improvements have resulted in a changeover time reduction from 65 minutes to 30 minutes.
  Keywords: Lean Six Sigma; LSS; DMAIC methodology; value stream mapping; VSM; changeover time.
  DOI: 10.1504/IJSSCA.2024.10068754
   
  
• Analysing the benefits of Lean and Six Sigma for myocardial infarction patients: a case study of an Indian hospital  
  by Gaurav Suman, Deo Raj Prajapati, Jeet Ram Kashyap 
  Abstract: Lean and Six Sigma as quality tools have proved themselves in healthcare sectors worldwide, but their use on myocardial infarction (MI) patients is minimal. The present paper shows the application of these quality initiatives to reduce door to balloon (DTB) time and door to needle (DTN) time for MI patients in a northern Indian hospital. The mean DTB time is calculated to be 349 minutes with a standard deviation of 206 minutes, whereas; mean DTN time is 113 minutes with a standard deviation of 50 minutes. The cause and effect diagram and value stream mapping tools were applied to identify various root causes and to minimise non-value-added time. The process cycle efficiency for the DTN and DTB processes is computed as 15.78% and 29.85% respectively. After implementing the proposed solutions, the duration of DTB and DTN processes has been reduced by 70.7% and 60.1% respectively.
  Keywords: Six Sigma; Lean; door to balloon time; DTB; door to needle time; DTN; myocardial infarction; MI; healthcare.
  DOI: 10.1504/IJSSCA.2024.10068755