Sigma Method Research Articles

Quality Control with Six Sigma Method to Minimize Polyester Fabric Product Defects at PT Sukuntex

Quality control needs to be done to face industrial competition. PT. Sukuntex is a textile industry that produces fabrics, one of which is polyester with 58% production from the total fabric production. PT. Sukuntex has a make to order fabric production system, the company carries out quality control by inspecting every fabric produced in the quality control division. In this study, an analysis of polyester fabric quality control using the six sigma method with the DMAI (Define-Measure-Analyze-Improve) steps to determine the DPMO value, the company's sigma level, the causes of defects, and improvements. The results of this study found 3 dominant defects based on the Pareto diagram, namely thin thickness, sparse, and dirty oil. In calculating the DPMO value, the result is 49,825.15 meters with the sigma value obtained is 3.15. The sigma value can increase with quality improvement. Therefore, the causes of defects were analyzed using a fishbone diagram which resulted in human, machine, method, and environmental factors. FMEA-AHP method for improvement priorities, where FMEA analyzes the ranking of the causes of defects, then prioritizes improvement based on weights with AHP. Improvement plan using the 5W+1H method at the improve stage.

Analisis Pengendalian Kualitas Produk Plastik Menggunakan Metode Six Sigma Dan Kaizen (Studi Kasus: PT Kusuma Mulia Plasindo Infitex)

PT Kusuma Mulia Plasindo Infitex is a company engaged in the manufacturing sector that produces polypropylene and HD (Hight density Polyethylene) plastic products. The problem that occurred at PT Kusuma Mulia Plasindo Infitex was that the number of defective products on HD plastic products of 98,327 kg contained 4,194 kg of defective products. The purpose of this study is to determine the factors that cause defects and suggestions for improvements to minimize defective products. This study uses the six sigma method which is useful for finding the root causes of problems that are adjusted to the characteristics of the data they have. The 5 stages of six sigma are DMAIC(define, measure, analyze, improve, control) and kaizen is the Five M-Checklist. So from the results of data processing, the value is obtained in the form of DPMO 8393.048 and a sigma value of 2.49. Proposed improvements include providing training in plastic welding, providing additional 5-10 minute breaks and supervision while working. Perform routine machine maintenance every month and cleaning every day. Adding ventilation and blowers in the production room. Carry out the production process according to the existing SOP at the company, especially in mixing materials according to the SOP for raw materials that have been made by the company.

Pengendalian Kualitas Menggunakan Metode Six Sigma dan FMEA untuk Mengurangi Reject Material Preform pada Industri AMDK

One of the stages of bottled drinking water production at PT X is bottle making using preform material. Preform material is made from PET (Polyethylen Terphtalate). During the production process, there are preform material rejects such as broken bottles, unstable bottle thickness, white preforms, pinched bottles, and white bottles. The total preform material rejects during January to October 2022 amounted to 0.98% or there were 234,504 pcs of preform rejects from the total production of 23,905,322 bottles. The percentage of preform material rejects is above the company standard of 0.5%, so it requires Six Sigma and FMEA methods to reduce these rejects. The proposed improvement recommendations are blowing machine operation checklist form, preform specification form for suppliers, and training schedule form. However, the recommendation that was implemented was the blowing machine operation form checklist because machine malfuction was the main factor causing preform material rejects based on FMEA analysis. The recommendation was implemented for one month in November and succeeded in reducing preform material rejects by an average of 0.86% or there were preform rejects of 298,641 pcs of preforms from a total production output of 34,599.74 bottles during January to November 2022. The final calculation after the implementation of the proposed improvements shows that there is a decrease in the DPMO value from 1961.93 to 1726.26 and an increase in the sigma level value of 4.42 sigma which was previously 4.38 sigma, from this value it shows that the sigma level has increased by 0.04 sigma.
 Keywords: Reject, Preform Material, Six Sigma

PRODUCTION QUALITY CONTROL ANALYSIS OF HARUM MANIS USING THE SIX SIGMA METHOD (CASE STUDY: MSME HARUM MANIS, LAMONGAN)

The Harum Manis was a popular traditional food in the 1990s made from sugar, flour, and food coloring. MSME Harum Manis is an MSME that produces harum manis snacks that have been in production since 2012. The author's observations found that the company had problems in its production process, namely, defective products. Types of harum manis product defects are stable fracture, rough fracture, and soft looseness. This research aims to identify the factors that cause product defects, calculate the sigma value in the production harum manis products, and provide suggestions for improving the quality control of harum manis production. The research uses the six sigma method with the concept of DMAIC (define, measure. analyze, improve, and control). The sample used in each data collection is 30 kg. The defect factors for the harum manis product are the slow gulali withdrawal process, the employees being less skilled, the lack of employee training, the addition of flour needs to be more stable, and the production room is now open. The sigma level obtained from MSME Harum Manis in October was 3.4, while in November, a sigma value of 3.28 was obtained. Proposed improvements include conducting training for new and old workers on an ongoing basis, making standard operating procedures (SOP) for workers, making SOP regarding the production process in detail, and closing the production room during production.

Study on Improving the Processing Efficiency of Mixing Production Line

In order to improve the processing efficiency of the mixing production line and enhance product competitiveness, lean Six Sigma method is adopted to solve the faults that affect the output efficiency of the mixing production line according to the DMAIC path, which can assist workers to increase the average daily output of product processing from 1.3 to 2.6 units. Lean Six Sigma method can deeply analyze the production faults of the hybrid production line and effectively solve the problem of product production efficiency.

Lean six sigma methodology for waste reduction in ship production

This study was conducted to reduce the amount of waste in ship production and assembly processes at PT ES. Several wastes during the ship production process result in the actual ship completion time being longer than the planning time set by the process planner. Therefore, accurate analysis is required to reduce waste. In this way, contributing factors can be identified, and more effective solutions can be obtained to reduce waste. This is done by implementing the Lean Six Sigma method (DMAIC processes) and several tools and methods, such as Pareto and fishbone diagrams and the FMEA method. The results show that the most critical potential root cause affecting production delays comes from the potential causes with the highest Risk Priority Number (RPN) value. The causes are welders who do not understand the WPS (RPN 432), unstable welding transformers (RPN 432), and unproductive loader movements (RPN 384). The recapitulation of welding defects produced in the production process at a sigma level of 2.48. Recommendations for the three potential critical wastes were made and planned for implementation. The estimated average RPN impairment for the three critical root causes was 32.3%. This condition will impact the total ship production time, which is 6% shorter (equivalent to 14 days) than the previous production time with a new sigma level of 2.55.

A New Approach to Production Process Capability Assessment for Non-Normal Data

The process quality capability indicators Cp and Cpk are widely used to measure process capability. Traditional metric estimation methods require process data to be explicit and normally distributed. Often, the actual data obtained from the production process regarding the measurements of quality features are incomplete and do not have a normal distribution. This means that the use of traditional methods of estimating Cp and Cpk indicators may lead to erroneous results. Moreover, in the case of qualitative characteristics where a two-sided tolerance limit is specified, it should not be very difficult. The problem arises when the data do not meet the postulate of normality distribution and/or a one-sided tolerance limit has been defined for the process. Therefore, the purpose of this article was to present the possibility of using the Six Sigma method in relation to numerical data that do not meet the postulate of normality of distribution. The paper proposes a power transformation method using multiple-criteria decision analysis (MCDA) for the asymmetry coefficient and kurtosis coefficient. The task was to minimize the Jarque–Bera statistic, which we used to test the normality of the distribution. An appropriate methodology was developed for this purpose and presented on an empirical example. In addition, for the variable after transformation, for which the one-sided tolerance limit was determined, selected process quality evaluation indices were calculated.

Quality Control on Bogo Helmet Coating Process Using the Six Sigma Method, Fault Tree Analysis (FTA) and Failure Mode and Effect Analysis (FMEA)

Hanesda Assembling Helmet is a private company engaged in the assembly of bogo helmets. One of the serious problems faced by this company is that the defective products produced in the production process reach 4% of the tolerance limit set by the company, which is 1.5%. The purpose of this research is to control the quality of the coating process which has a lot of product defects. The method used in this study is the Six Sigma method with the stages of DMAIC. The method used to analyze the causes of failure is the FTA method and the method used to determine the weighting in prioritizing the repair design is the FMEA method. The results of the research using the Six Sigma method are obtained DPMO values of 19,931 with a Sigma level of 3.57. Types of defects that have the highest RPN are streak defects, flex defects, uneven paint defects and paint runs defects with an RPN value of 112. High RPN value will be prioritized for improvement plans.

Distribution of cardiorespiratory fitness in children and adolescents at different latitudes.

To explore the differences and characteristics of cardiorespiratory fitness (CRF) among children and adolescents in regions with different latitudes in China. A total of 9892 children and adolescents aged 7-22 years were selected from seven administrative regions in China by the stratified cluster random sampling method. CRF was measured by performance on the 20 m shuttle run test (20mSRT) and estimated maximal oxygen consumption (VO2max ). One-way ANOVA, one-way ANCOVA, and the Lambda Mu and Sigma methods were used to analyze the data. Overall, the VO2max of children and adolescents at high latitudes was significantly lower than that of children at low and middle latitudes. The P10 , P50 , and P90 20mSRT values for children and adolescents of most age groups in high latitudes were less than those in low and middle latitudes. The 20mSRT-Z and VO2max -Z scores among children and adolescents aged 7-22 in high latitudes were lower than those in middle and low latitudes after adjusting for age, per capita gross domestic product (GDP), and per capita disposable income. In general, the CRF of children and adolescents at high latitudes was less than that at low and middle latitudes. Effective measures should be taken to improve CRF in children and adolescents at high latitudes.

Product quality control analysis using the six sigma method

Product quality control analysis using the six sigma method

The development of a lean six sigma and BIM framework for enhancing off-site manufacturing

PurposeThis study aims to improve a construction company's overall project delivery by utilising lean six sigma (LSS) methods combined with building information modelling (BIM) to design, modularise and manufacture various building elements in a controlled factory environment off-site.Design/methodology/approachA case study in a construction company utilised lean six sigma (LSS) methodology and BIM to identify non-value add waste in the construction process and improve sustainability.FindingsAn Irish-based construction company manufacturing modular pipe racks for the pharmaceutical industry utilised LSS to optimise and standardise their off-site manufacturing (OSM) partners process and leverage BIM to design skids which could be manufactured offsite and transported easily with minimal on-site installation and rework required. Productivity was improved, waste was reduced, less energy was consumed, defects were reduced and the project schedule for completion was reduced.Research limitations/implicationsThe case study was carried out on one construction company and one construction product type. Further case studies would ensure more generalisability. However, the implementation was tested on a modular construction company, and the methods used indicate that the generic framework could be applied and customized to any offsite company.Originality/valueThis is one of the few studies on implementing offsite manufacturing (OSM) utilising LSS and BIM in an Irish construction company. The detailed quantitative benefits and cost savings calculations presented as well as the use of the LSM methods and BIM in designing an OSM process can be leveraged by other construction organisations to understand the benefits of OSM. This study can help demonstrate how LSS and BIM can aid the construction industry to be more environmentally friendly.

Body composition reference charts for infants from birth to 24 months: Multicenter Infant Body Composition Reference Study

BackgroundBody composition assessment in the first 2 y of life provides important insights into child nutrition and health. The application and interpretation of body composition data in infants and young children have been challenged by a lack of global reference data. ObjectivesWe aimed to develop body composition reference charts of infants aged 0–6 mo based on air displacement plethysmography (ADP) and those aged 3–24 mo based on total body water (TBW) by deuterium dilution (DD). MethodsBody composition was assessed by ADP in infants aged 0–6 mo from Australia, India, and South Africa. TBW using DD was assessed for infants aged 3–24 mo from Brazil, Pakistan, South Africa, and Sri Lanka. Reference charts and centiles were constructed for body composition using the lambda–mu–sigma method. ResultsSex-specific reference charts were produced for FM index (FMI), FFM index (FFMI), and percent FM (%FM) for infants aged 0–6 mo (n = 470 infants; 1899 observations) and 3–24 mo (n = 1026 infants; 3690 observations). When compared with other available references, there were observable differences but similar patterns in the trajectories of FMI, FFMI, and %FM. ConclusionsThese reference charts will strengthen the interpretation and understanding of body composition in infants across the first 24 mo of life.

Implementasi Metode Six Sigma Dalam Pengendalian Kualitas Produksi Di Industri Tekstil Sarung Tenun (Studi Kasus: Ud. Boi Tulus)


 Boi Tulus in Balige is one of the industries engaged in the processing of woven sarongs. In order for a product to be said to be of high quality, the product must meet the specifications that have been set. To obtain a quality product, a quality control measure is needed. Quality control carried out at UD. Boi Tulus has not been carried out optimally on woven sarong products. There are obstacles that result in the quality of the woven sarong products that are not in accordance with standards, such as the discovery of defects. For that, a quality improvement action is needed at UD. Boi Tulus so as to be able to produce quality sarong products. The use of the Six Sigma method in quality control at UD. Boi Tulus is the right step in dealing with the problems faced in the industry. Based on data processing, the percentage of defects in woven sarong products at UD. Boi Tulus for the period May 2021-March 2022 is 5-9%. By using the DMAIC approach, there are 4 categories of defects in the weaving gloves, namely uneven color defects, sizes not according to specifications, torn thread defects, broken thread defects or knots. After calculating the value of DPMO on UD. Boi Tulus is 10,884 with a Sigma level value of 3,800. This means that from a million opportunities, there will be a possibility of 10,884 UD. Boi Tulus, can not meet the quality control standards carried out. Furthermore, fishbone tools are used to analyze the factors causing defects in weaving gloves, then recommendations for improvement are given in the form of SOPs and supervision is carried out in the form of control check sheets. After implementation, there are changes, namely a decrease in the value of DPMO to 4.462 and the Sigma level to 4.1239.
 
 
 Keywords : Quality Control, Defect, DMAIC, Six Sigma

Penerapan Metode Six Sigma Dengan Konsep DMAIC Sebagai Alat Pengendalian Kualitas Produk

This study aims to determine the value of sigma before improvement is carried out and find out the causes of defects in the production process, as well as produce proposals for improvement and quality control of products. The population in this study was Arsel furniture table products during April 2015 to March 2016 which amounted to 420 products. Sampling using purposive sampling techniques and with the considerations used, the number of samples used was 306 samples. The results of research using the Six Sigma method with the DMAIC concept as a product quality control tool in Arsel Mebel found defective products in the form of rupture during cutting, removal of laminate materials, size errors, and the process of drilling table legs. The results of the analysis showed that the defective product that was more dominant was broken at the time of cutting, which was 38 percent.

Effectiveness of six sigma score analysis of clinical biochemistry parameters in a newly installed automated analyser– Retrospective analysis in a tertiary cancer care centre

Quality assurance is need of the hour in a laboratory. Clinician’s decision regarding treatment modality is based on the laboratory results on most occasions. So to ensure accuracy of results reported periodic evaluation as per standard criteria and audit is necessary. Six sigma is one such tool to apply in day to day practice for monitoring and enhancing performance of a laboratory. A new machine is a new challenge for a laboratory from validation to reporting of quality result with assurance for which six sigma is invariably a necessary method. So this study was taken up to check for month wise status of six sigma and performance of clinical chemistry analyser for 20 different analytes.: It was a retrospective study and data required for the study were collected from March 2020 to November 2020 in clinical biochemistry laboratory of Tata Medical Centre Kolkata, West Bengal. Test parameters were analysed on Vitros 7600 automated analyser. Data collected were IQC-coefficient of variation percent (CV %) and proficiency test -Bias%. Six sigma score were analysed monthly using standard formula applicable. We obtained an excellent performance (> 6 sigma) for test parameters CK, Urea, Creatinine, Uric acid, albumin, Calcium, Phosphorus, Magnesium, AST, ALTV, ALKP, GGT, Lipase, LDH in both level of IQC and for sodium and amylase in level 2 IQC. However we noticed poor performance (<3 sigma) for test parameters Glucose, potassium, chloride, TP in both level IQC and for sodium and amylase in level 2 IQC.QGI score analysed to find out root cause and corrective action. Monitoring IQC and EQAS with six sigma method helps evaluation and improvement of performance of a laboratory even with a new machine. It supports root cause analysis and necessary corrective and preventive action.

Improvement of Plastic Manufacturing Processes by Six Sigma and DMAIC Methods

Improvements are required in any industry to maximize productivity by reducing faults in any method and removing overall waste produced within the manufacturing facility. This study examines the problems faced by some leading companies in the plastic manufacturing industry, such as Motorola, General Electric, and Zamil Plastic and how to solve them. In this study, the key difficulty in this plastic manufacturing industry was black dots, which can be seen in injection molding operations. When compared to other faults, the injection molding technique result shows that black dot defects are the main reason for rejects in May, making up almost 41% of all rejects. Because, Defectives Per Million Opportunities (DPMO) of products in Plastic Remote Controls (PRC) result in numerous wastes, statistical quality control (SQC) methods, such as the Pareto chart, cause-effect diagram, and control chart were utilized to examine the data. Also, this study shows that the time necessary for tool changeover was extremely long, resulting in a significant wait for manufacturing because multiple dies and molds were required for production (types of plastic fuel tanks). The novelty of this research is that it clarifies when the company uses six sigma and the DMAIC method to rapidly discover the problem in the products and find a suitable solution to save time, effort, and cost. Run charts and the layout of mold storage are used to solve the problem and ensure that the process is truly improved by reducing the time it takes to change over for tools and dies.

Quality Control To Reduce Defects in Ceramic Production Using Six Sigma Method and Root Cause Analysis

PT. Kualimas Aditama is a company engaged in the manufacturing sector. This company has been a ceramics producer for 23 years. However, the problem faced in this company is that the level of product defects produced exceeds the company's tolerance limits. The company provides an acceptable tolerance for defective products of 3, but in fact the production of 60x60cm ceramics for 6 months in February 2023 had a product defect of 3.2% exceeding the tolerance limit which had a defect value of 1505 Pcs and a DPMO value of 8064.68899 with a sigma level of 3.9. In the define stage there were 4 product defects that occurred, namely ripe gupil of 2,668 pcs, raw gupil of 2,158 Pcs, ceramic scratched of 1,255 pcs and edge cracks of 586 Pcs. This study aims to determine damage to ceramics, determine the level of defects in ceramics and provide suggestions for improvements to reduce the number of defects. As an effort to reduce product defects that occur at PT.Kualimas Aditama, it is necessary to carry out quality control using the Six Sigma and RCA methods to improve production quality. From the results of the analysis, it is obtained that the triggering factors for product defects include human, machine, environmental factors.
 Highlights :
 
 Six Sigma Approach: Utilizing Six Sigma methodology for quality control allows for systematic problem-solving and process improvement.
 Root Cause Analysis (RCA): Identifying root causes of defects is crucial for implementing effective corrective measures.
 Human, Machine, Environmental Factors: Recognizing and addressing these factors are essential in reducing product defects and improving production quality.
 
 Keywords – Quality Control, Six Sigma, Root Cause Analysis

Plumbing Work in Green Market Based on Value Engineering

The green traditional market concept begins with the structure of the market section. This concept consists of various ideas that make markets environmentally friendly, these ideas include composting buildings, open gardens, bathrooms/toilets, parking areas and planting in the market. Understanding Value Engineering in general is a management technique that uses a systematic approach, creative and organized effort that is directed to analyze the function of a system with the aim of achieving the required function at the lowest possible cost. However, this remains within the established technical functions and limits. The method used is value engineering with the aim of understanding and identifying obstacles in the application of value engineering and lean six sigma methods in dirty water installation work in market buildings with the concept of green building. The research instruments were arranged in the form of variables which were formulated in the form of questions (questionnaires). Cost efficiency was obtained in clean and dirty water installation work of a savings of 9.8%.

Relationship among Safety, Quality and Productivity in Construction Projects

Construction is thought to be the most dangerous business due to its unique nature. To reduce risks and boost productivity in the construction industry, quality and safety management is required. The research examines productivity, quality, and safety in terms of their participation in and effects on the execution of building projects. Safety is given first priority throughout construction, with a focus on hazard detection and the prevention of workplace injuries and accidents. There is an examination and provision of the legislation requiring safety programs, training, and obligation to safety standards. Underlined the significance of safety issues at the design stage. The research also discusses safety of building and the importance of building codes in preventing structural failure, as well as factors that influence building failure and techniques for preventing them. The paper introduces quality through the lens of recent total quality management. Quality control, quality management, quality assurance, and Six Sigma concepts are addressed with examples in relation to building quality and structural integrity. Finally, concepts of productivity are provided, with an emphasis that good project management reduce productivity losses and the use of lean construction and lean Six Sigma methods to complement them. Finally, the report summarizes the relationship among safety, quality, and productivity.

Analisis Pengendalian Kualitas Pada Produk Roti di PT. Bapak Bakery

PT. Bapak Bakery is a food processing company, especially bread with various types of products. The types of product defects that are often encountered are inappropriate shape, inappropriate size and charred. The purposes of this study were to determine the level of defect in bread products at PT. Bapak Bakery, to know the factors that cause defective products that often occur in PT. Bapak Bakery, as well to formulate the recommendation of improvement efforts to overcome defective products that often occur in PT. Bapak Bakery. Data analysis used the six sigma method through five stages, namely define, measure, analyze, improve, and control (DMAIC) and followed by the Failure Mode and Effect Analysis (FMEA) method used in the Analyze stage. The results showed that the product sigma values ??1, 2, and 3 were at the level of 3.93, 3.86 and 3.09, these values ??had not yet reached the level of 6 sigma. Product sigma values ??1, 2, and 3 indicate the possibility of product defects of 7.852, 9.457 and 56.956 for one million opportunity. PT. Bapak Bakery needs to do quality control to achieve the target of zero defects. Factors causing product defects were human factors, method factors, raw material factors and machine factors. Suggestions for improvement that can be done are holding regular training for workers, including SOPs for making bread in each room of the production process, increasing supervision starting from the selection of raw materials, weighing materials, production processes, permanently listing measuring instruments on the production table, as well as the use of kanban cards and timers to simplify the baking process.