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Bus Rapid Transit (BRT) systems play a crucial role in providing efficient and sustainable urban mobility, yet service quality often faces challenges that lead to passenger dissatisfaction. This study focuses on BRT Trans Jateng Corridor 7, which has received a considerable number of complaints regarding service reliability, comfort, and punctuality. The main objective of this research is to improve passenger satisfaction by applying the Six Sigma methodology to identify, analyze, and reduce the root causes of service-related complaints. Using the DMAIC (Define, Measure, Analyze, Improve, Control) framework, data were collected through complaint reports, passenger surveys, and operational performance indicators. Statistical analysis and cause-effect diagrams were employed to pinpoint critical factors influencing complaints, including bus frequency, driver performance, ticketing efficiency, and infrastructure support. The findings indicate that the application of Six Sigma significantly reduced recurring complaints, particularly in the areas of schedule adherence and service responsiveness, leading to measurable improvements in overall passenger satisfaction. The synthesis of results demonstrates that structured quality management approaches such as Six Sigma can effectively enhance public transportation service quality by providing systematic solutions to operational problems. In conclusion, this research highlights the practical benefits of Six Sigma in improving service performance and reducing passenger complaints, offering valuable insights for policymakers and transportation operators seeking to strengthen the quality and sustainability of public transit systems.

The purpose of this research is to use the six sigma approach to assess the quality of cracker manufacturing at UD. Palapa in Nganjuk Regency. This technology was chosen because it allows for quantitative measurement and analysis of product defect levels, as well as the identification of defect-causing variables. The study was carried out using the DMAIC (Define, Measure, Analyze, Improve, Control) steps and statistical methods such as Pareto diagrams, fishbone diagrams, and C-chart control charts. According to the research, the cracker manufacturing process at UD. Palapa has an average sigma value of 2.74, which is still below the six sigma (6σ) threshold.  This figure implies that the product fault rate remains fairly high.  The most common forms of faults are irregular shape and uneven thickness, which are mostly produced by machine, human, process, and raw material problems. C-chart analysis reveals that most processes are still under control, while there are a few spots beyond the control boundaries that indicate unique variances. Based on these data, it is possible to infer that UD. Palapa's quality control system is still reactive and has to be improved in order to be more proactive. Routine equipment maintenance, operator training, the introduction of standard operating procedures (SOP), and more stringent raw material selection are all possible efforts. Six Sigma deployment has been shown to provide a full view of production quality conditions, as well as a foundation for future continuous improvement programs.

Increasing business competition requires companies to consistently improve quality and operational efficiency. This study aims to identify and reduce non-value added activities in the procurement process at Distributor X, a company engaged in the distribution of instant cooking spices. Common issues include expired goods (49.05%), damaged packaging (18.78%), and product mismatches (32.17%). The Lean Six Sigma approach with the DMAIC (Define, Measure, Analyze, Improve, Control) method is used to address these problems. Measurement results show an average DPMO value of 10,076.58 and a sigma level of 3.82, which are still far below the Six Sigma quality standard. Improvement proposals include the implementation of barcode/RFID systems, FIFO inventory management, higher-quality packaging materials, and the use of unique product codes. In the Control phase, monitoring is carried out through an ERP system and the establishment of structured SOPs to support distribution oversight. This approach demonstrates potential in reducing defect rates and improving the overall quality of the procurement process.

UMKM Tahu XYZ, a small-scale tofu producer, is currently facing significant challenges in maintaining consistent product quality, primarily due to a high defect rate. Common issues identified include crumbled tofu shapes, overly soft textures, and inconsistent taste, which negatively impact customer satisfaction and business sustainability. This study aims to investigate the root causes of these quality issues and propose practical solutions using the Lean Six Sigma methodology. The research employs a descriptive quantitative approach through the DMAIC framework—Define, Measure, Analyze, Improve, and Control—to ensure systematic problem-solving. Data were collected over a six-month period through direct observation, structured interviews, and review of production records. The analysis identified four dominant types of waste within the production process: unnecessary transportation, product defects, excessive movement, and over-processing. The root causes of these inefficiencies are linked to poor handling of raw materials, variability in soybean quality, and an ineffective production layout that hampers workflow and consistency. To address these problems, the study proposes several targeted interventions, including the redesign of the production layout to optimize flow, the implementation of the 5S (Sort, Set in order, Shine, Standardize, Sustain) workplace organization method, the development of standardized operating procedures (SOPs), and the adoption of improved soybean boiling technology. The implementation of these improvements is projected to significantly reduce product defects, enhance process efficiency, and ultimately increase customer satisfaction. Furthermore, these actions are expected to improve the overall competitiveness of UMKM Tahu XYZ within the highly demanding food industry sector. This research provides actionable insights for other micro, small, and medium enterprises (MSMEs) seeking to apply structured quality control methods to strengthen operational performance and long-term business resilience.

This study aims to analyze and improve the quality control of packaging printing production at PT XYZ by applying the Lean Six Sigma methodology. Lean Six Sigma combines waste reduction principles with statistical quality control to achieve operational excellence. The research identifies major production challenges, including high defect rates, overproduction, and ineffective inventory management, all of which contribute to increased costs and reduced efficiency. The DMAIC framework—Define, Measure, Analyze, Improve, and Control—was employed to systematically address these issues. During the Define and Measure phases, types of waste were identified and defect rates were calculated using Defects Per Million Opportunities (DPMO). In the Analyze phase, root causes were examined using a Fishbone (Ishikawa) diagram, highlighting factors related to manpower, materials, machines, and methods. The analysis revealed a sigma level of 3.2, indicating a moderate level of process quality and substantial room for improvement. To address the identified issues, several improvement strategies were proposed. These include implementing a Just-In-Time (JIT) system to reduce inventory waste, adopting the First-In-First-Out (FIFO) inventory method for better material rotation, and conducting targeted technical training for operators to minimize human error. In the Control phase, the study suggests process standardization, routine inspections, and continuous monitoring as key practices to ensure that improvements are sustained over time. The findings and recommendations from this study are expected to contribute to better quality control, reduced operational waste, and enhanced productivity in the packaging printing process. Ultimately, this approach aims to strengthen PT XYZ’s competitiveness in the printing industry by fostering a culture of continuous improvement and quality excellence.

Metode pendekatan DMAIC dapat membantu pengelola lembaga pendidikan terkhususnya kepala sekolah sebagai pemimpin untuk mengembangkan sekolah lebih lanjut. Metode DMAIC adalah sebuah pendekatan melalui pengendalian dan perbaikan pada kualitas dengan beberapa tahapan yang dimulai dari pengidentifikasian masalah sampai dengan tahap akhirnya yaitu melakukan pengendalian dan pemberian usulan untuk melakukan perbaikan. Peneliti melakukan observasi menggunakan metode penelitian kualititatif untuk menjawab masalah penelitian data. Metode ini biasanya terdiri dari narasi yang diperoleh dari wawancara, observasi, dan penelitian literatur. Tujuan adanya penelitian ini adalah untuk mendeskripsikan implementasi Total Quality Management (TQM) dengan metodologi DMAIC pada perbaikan secara berkelanjutan di SMK Negeri 1 Surabaya. Continuous improvment dalam TQM melalui pendeketan DMAIC pada lembaga pendidikan di SMK Negeri 1 Surabaya telah dilaksanakan dengan baik, dengan berdasar pada ISO dan selalu memprioritaskan permsalahan yang berhubungan siswa. Dalam mengidentifikasi masalah yang terjadi, sekolah telah menggunakan data yang akurat dengan survey dari pihak pihak yang dilibatkan baik eksternal maupun internal. Pengontrolan implementasi dari solusi permasalahan juga dilakukan secara baik yaitu secara berjalan tidak menunggu evaluasi pada akhir pelaksanaan.

Micro, Small, and Medium Enterprises (MSMEs) play a strategic role in Indonesia’s economy, including in the garment industry. The subject of this study is MSME X, located in Cimahi City, which specializes in the production of knitted clothing. This research aims to identify production problems, analyze the causes of defects, and design improvement strategies using the Six Sigma method with the DMAIC (Define, Measure, Analyze, Improve, Control) approach. In the Define stage, the main problems are identified through the Critical to Quality (CTQ) approach, which reveals three major types of defects: button defects (39%), stitching defects (32%), and fabric or pattern defects (29%). Next, the Measure stage is conducted to assess process performance using quality indicators. The calculation results show a Defects per Million Opportunities (DPMO) value of 10,968.95 and a Sigma Level of 3.79, indicating room for improvement. The Analyze stage utilizes Pareto and Fishbone diagrams to identify root causes. The Improve stage applies Failure Mode and Effect Analysis (FMEA) to determine improvement priorities. The Control stage involves the use of Statistical Process Control (SPC), regular inspections, and an incentive system. This approach is expected to reduce defect rates and sustainably improve production efficiency.

UD. Sarigut Bakery is known as one of several industries that focus on processing bread specifically in the Banda Aceh City area that seeks to produce with a variety of bread. The purpose of this study is to carry out efforts to identify, measure efforts, and analyzing efforts to the phase known to be the cause of the decline in quality of the production process of meses bread through a series of stages of the DMAIC SIX SIGMA methodology. It is known that the main problem is the discovery of disability with a total of 4,096 of the total production of the production of 21896 with a period of 3 months specifically in the dominant disability of Meses bread in the percentage of 81.29%. With the dominant of the disability itself the disability that comes in damaged bread with a percentage of 36.49% present from all of the total disability of related meses bread. After the assessment effort, the DPMO value was obtained by 26723.74 so that there were several levels of Sigma 3, which means it was still far from the world industry level which reached 6σ (3.4 DPMO). Efforts to analyze the data carried out by applying the Fishbone and FMEA (Failure Mode and Effect Analysis) diagrams are known to be related to the cause of the presence of disability from damaged bread with 3 modes of failure in potential, namely bread that is not filled with chocolate with a value of 20, the upper bread with a value of RPN of 80 and failure mode on broken bread with the highest RPN value of 90.

The research took place at Wastec Internasional Company, a company engaged in environmental waste processing services. The oil from the crude oil waste processing treatment process still has Basic Sediment and Water (BS&W) content and oil content that is too high so that it cannot reach the established standards so that the company must make efforts to reduce waste from the production process. The purpose of the study was to determine the sigma value, the number of defects and factors causing quality failure in crude oil processing treatment at PT Wastec Internasional. The methods used are the DMAIC method, control maps and fishbone diagrams. The calculation results obtained an average BS & W sigma value of 3.4 and an oil content sigma value of 3.29. The average number of defects for BS&W was 9.075% and for oil content was 2113 mg/L. The factors causing treatment quality failure are material, method and environmental factors.

Operational efficiency and product quality are crucial for enhancing the competitiveness of MSMEs in the era of globalization and digital transformation. This study explores the application of Six Sigma to reduce product defects at MSME X, a footwear manufacturer in Bandung. Using a quantitative approach with interviews, documentation, and observation, the research applied the DMAIC (Define, Measure, Analyze, Improve, Control) framework to identify and address quality issues. Key defects included joint cracks, under-fill, and press marks. Analysis using Pareto charts and cause-and-effect diagrams revealed root causes such as inadequate operator training, inconsistent raw materials, and irregular machine maintenance. To address these, the company implemented retraining programs, improved standard operating procedures, and adopted digital monitoring systems. As a result, the defect rate was reduced by 40%, and the sigma level improved from 3.9 to 4.45. The study confirms that Six Sigma can significantly enhance both product quality and operational performance. These findings offer valuable insights for other MSMEs aiming to adopt structured quality improvement methods to remain competitive in the global market.

One of the key processes in the production of APAR cylinders is the welding of cylindrical plates, which is carried out using a Longitudinal Welding Cylinder machine and the CO₂ welding method. However, in practice, operators face several challenges, mainly due to the number of process steps that do not significantly contribute to the quantity or quality of the output, resulting in reduced productivity. This study aims to improve the productivity of the welding process through a series of improvements. The methods used include data analysis and root cause identification through the Overall Equipment Effectiveness (OEE) approach and Lean Six Sigma using the DMAIC stages (Define, Measure, Analyze, Improve, Control). Based on the Define stage, the initial OEE value was 67.49%, which is still far below the world-class standard of 85%. In the Measure stage, Pareto analysis revealed that the largest downtime (2,097 minutes or 40%) was caused by cycle time issues. Further analysis showed that activities such as material setup, additional plate placement, and additional plate cutting (totaling 85 seconds) could still be optimized. During the Improve stage, modifications were made, such as eliminating the additional plate cutting process and adding a stopper to ensure accurate welding alignment. These improvements successfully reduced the cycle time from 180 seconds to 120 seconds, thereby decreasing downtime and increasing the OEE value to 76.12%.

Product quality is a key factor in enhancing a company's competitiveness. PT Nugraha Potong Tekuk, a producer of MPGG products, experienced a significant increase in the defect rate, reaching 11% of total production during the period from June 24 to July 16, 2024. This study aims to analyze the defect rate, identify the main causes, and provide improvement recommendations. The study follows the Six Sigma methodology, including the Define, Measure, Analyze, Improve, and Control (DMAIC) phases. Based on P-Chart analysis, the production process is within statistical control limits, but the defect rate still requires improvement. Two main types of defects were identified: unevenness and size defects, each accounting for 50% of the total defects. Fishbone diagram analysis revealed four main contributing factors: people, machines, materials, and environment. The people factor includes lack of operator skills and operator fatigue, while the machine factor covers worn-out tools and uncalibrated measuring instruments. The material factor is related to low-quality raw materials, and the environmental factor includes poor lighting and unstable work surfaces. Improvement recommendations include operator training, routine machine maintenance, quality control of raw materials, and improvement of the work environment. This study is expected to help PT Nugraha Potong Tekuk enhance product quality, reduce defect rates, and maintain competitiveness in the market.

Batik Banten Mukarnas is a company that produces stamped batik designs with various patterns and varieties of batik. Problems frequently arise in the company due to increased stamped batik production capacity to meet the demand for stamped batik design products, which continues to rise from stamped batik suppliers. Another impact of growing demand capacity is the high number of defects in stamped batik cloth products, because overall, the company's management, including human resources, tools, and methods, is not prepared for the increase in production capacity to meet the surge in consumer demand, resulting in an impact on the quality of the products produced—consequently, the organization endeavors to regulate the quality of stamped batik cloth at PT. Batik Banten Mukarnas establishes objectives that employ Six Sigma with the DMAIC method (Define, Measure, Analyze, Improve, and Control) in the production of batik stamp designs to meet production objectives. The results of the data processing that has been done obtained a sigma value before improvement for 3 CTQ of 3.54. After improvement, the sigma value increased to 3.86. While for the sigma value before improvement for 1 CTQ of 3.04, the sigma value increased to 3.42 after improvement. The factors contributing to defective products, as illustrated by the fishbone diagram, include methods, personnel, materials, machinery, and environmental conditions. The division leader consistently oversees and regulates operations, enhances the number of brushes, and trains operators to ensure proficient adherence to standard operating procedures (SOP).