Papers by Keyword: Six Sigma

Abstract: Plastic water tanks made from FDA-approved Polyethylene (PE) are widely used due to their advantageous qualities, including being free of heavy metals, UV-stable, odorless, durable, and suitable for food-grade applications. A rotational molding process creates a smooth inner surface without corners, reducing dirt adhesion. However, a case study revealed pore defects on the outer surface of the tanks, compromising UV stability and customer satisfaction. This study aims to address these pore defects by establishing new standards and improving both internal processes and external factors affecting mold heating. Utilizing Six Sigma methodology, the study employs data analysis and design of experiments (DOE) to identify and regulate critical parameters affecting the manufacturing process. The Six Sigma approach, which encompasses the Define, Measure, Analyze, Improve, and Control (DMAIC) phases, was applied to enhance process capability, minimize variations and machine errors, reduce waste, and increase customer satisfaction. By effectively addressing the root causes of porosity defects, the study aims to improve processes and enhance product quality.

Abstract: This research focused on defects reduction in spheroidal graphite iron casting process of a jackscrew manufacturer in which graphite nodularity was lower than a given specification (75%). This situation could lead to serious issues and accident to end-users. The Six Sigma approach of DMAIC was employed to identify and eliminate the problems. The result obtained after implementing the Six Sigma showed that the process capability was improved from-0.47 to 2.04, and the average per cent graphite nodularity was increased significantly from 61.49% to 86.43%.

Abstract: This research was conducted in a manufacturing company that produces integrated circuits for global customers. The purpose of this research was to reduce defect rate from the assembly department that affected to product lots on hold at the test department for the contactless chip module package which had an increasing product lots on hold rate of 9.5% in March 2019 based on the reject criteria V_limiter (REQA). The potential cause of defect came from die crack. In order to reduce defect rate, the 5 steps of DMAIC Six Sigma methodology were applied in this research to identify the root cause of the problem and establish effective actions. After the improvement, the product (lots) on hold criteria V_limiter (REQA) was reduced from 9.5% to 5.82% in July 2019.

Abstract: The purpose of this research is to reduce the defect rate from the manufacturing process of in-mould decoration (IMD), the process combining PET film with decorative patterns are moulded together with ABS resins, which has been developed to reduce the secondary process of decorative screen printing. Recently, the case study company has produced components with a high defect rate, which increased sharply to 22.3% in June 2018. The major causes of the defect resulting from PET film peeled off. In order to reduce the defect rate, the five steps of the DMAIC Six Sigma methodology are implemented. The detail of the IMD manufacturing process was studied to identify appropriate measurement methods and factors affecting PET film peeled off by using the cause and effect diagram and its scoring matrix. Then the prioritized factors were analyzed and selected from FMEA to conduct the design of experiment (DOE) to find significant factors and optimal parameter settings for improvement and control process to prevent reoccurrence. After improvement of PET film peeled off by setting appropriate parameter as well as implementing control plans and Standard Operation Procedure (SOP) to eliminate other defects from in-mould decoration process, the result shows that the defect rate of in-mould decoration process decreased from 22.3% to 0.7% in July 2018.

Abstract: The objective of this research is to improve the overall result and pass percentage of students in degree level technical institutions by eliminating the failure causes using lean six sigma method. A case study was carried out in a degree level technical institute, which has a total intake of 720 students producing 54% of results for the past five years. Taking as a challenge issues to produce more than 75% of results, it was considered to carry out a study using lean six sigma approach. In this research five stage methodology of six sigma i.e. DMAIC have been used to reduce the parameters that affect the system. Failure mode effect analysis, histogram, process capability analysis and fish bone diagram methodologies were also adopted to analyze the depth of the issue and to identify the critical factors that requires to be controlled and to improve by implementing the solutions and remarks received from the stakeholders. From the results it was found that, through this approach the pass percentage level of the technical institute had increased from 54% to 75% by identifying and reducing the appropriate source of failures.

Abstract: Lean Six Sigma tools are widely being applied in various manufacturing units of different sizes; still there is an apprehension among the industry regarding the benefits reaped from the implementation of this tool. Under this background, this paper attempts to explain the benefits of these tools implemented in a medium scale unit to improve a particular process. The various steps involved in implementation and the results are analyzed for the purpose of this study and explained in this paper.

Abstract: Quality is an important dimension or factor in any process or product. Success of the product or process depends on the application of knowledge assimilated on various subjects from theory into actual application; otherwise it would result into a quality defect, as a consequence of knowledge gap. One such quality defect in the product and the process is conversion of student into an Engineer by the Engineering Educational Institution is lower employability, a concern for society, employers and stake holders of the educational process. Causes for such defect, are multi-dimensional, requiring a multi-pronged approach in developing solutions. Regulatory bodies like AICTE, Industrial bodies like CII etc. in India, are working towards delivering solutions at the macro level of the Nation, while the issue also requires solutions to be deployed at the micro level of Institutions. Focus of this research work is to address one such element related to measurement of Quality dimension, quantify such knowledge gap with practicing professionals of the Industry, identify their significant presence by experience segments and relate them with student’s knowledge gap for similar element / dimension as found in literature. The work delivers a simple model which can be adopted in educational institutions that shall benefit the Industry and Engineering graduates. The scope of this work also includes explaining high level process map of the educational process with SIPOC and COPIS Quality model of Six Sigma in bringing out the complexity in educational process. This research work is a part of the ongoing research of the first author.

Abstract: The current paper describes the application of the Six Sigma methodology for reducing the number of scrapped parts on the manufacturing line at Start Transmission Comp. The paper shows how the five steps of the method, namely Definition, Measurement and Analysis, Improvement and Control, are applied, as well as the methods and quality tools used.

Abstract: The problem of quality and customer orientation are the most important leverage in obtaining success. Over the time, the influence of human resources in terms of training, controlling and shaping client expectations has gained significant meanings. Research in this field has led to the formulation of the hypotheses according to which human resources can represent a vital element in obtaining a competitive advantage. In line with the importance of the topic addressed, the main objective of these scientific approach is to identify the current problems related to the quality of Romanian tourism services and to propose a improvement program using the six sigma method. The paper provides an excellent resource for many researchers who are engaged in research and applications of Six Sigma in the tourism industry. Moreover the dearth of literature on the use of Six Sigma in the tourism sector makes this paper count.

Abstract: This paper is intended to determine all significant factors affecting one of the most important characteristic of connecting rod that is coaxiality, in one of the main suppliers of this part in Middle East, in order to achieve the optimum combination and levels of these factors. By sampling the connecting rods produced under different levels of factors and combinations, and measurement of non-coaxiality, enough data is gathered. To determine meaningful impact of each intended factor and to specify all effective and ineffective factors, the authors have used DOE method. Achievement of best combination consists of affecting factors is defined through DMAIC cycle steps to reduce the non-coaxiality defect and to reach intended sigma values for the production process. According to the analysis of the results, better rate of non-coaxiality is obtained.