Reliability, availability and maintainability analysis of a bag production industry based on the six sigma DMAIC approach

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Panagiotis Tsarouhas

Purpose The purpose of this paper is to implement the six sigma (SS) strategy in a bag sector under actual operating circumstances based on defining-measure-analyze-improve and control (DMAIC). During the project, several statistical tools and methods have been used efficiently to create inferences. Thus, to measure and enhance system efficiency, the author calculate reliability, availability and maintainability (RAM) indices. Based on this research, the author show how the SS method and RAM analysis are very helpful in determining maintenance intervals, as well as in planning and organizing the appropriate maintenance strategy. Design/methodology/approach This study introduces the step-by-step application of the DMAIC methodology for the identification and reduction of bag production line downtime and examines the present operations management. Thus, statistical techniques are used to analyze the failure and repair database. Pareto analysis, histograms and descriptive statistics at the machine and line-level of the historical data were conducted. Trend and serial correlation testing validated the hypothesis of independence and identical distribution of database was performed. In addition, with their best fit allocation, the RAM of both the bag production line and its machines was estimated at separate mission times. Findings The main goals of the applied method are to understand the nature of the downtime patterns and to accurately and quantitatively estimate the RAM characteristics of the bag production system. The assessment defines the production line's critical points, requiring further enhancement through an efficient maintenance approach. Therefore, by improving plant efficiency and safety, the author can decrease unplanned downtime and equipment failures. Originality/value This research is expected to serve as an attempt to conduct SS DMAIC methodology through RAM assessment and its impact on system efficiency under actual circumstances. The benefit of the methodology is that the manufacturing process is continuously monitored by suitable indicators, the use of which leads to a continuous improvement cycle.

2019 ◽  
Vol 69 (5) ◽  
pp. 1009-1032 ◽  
Author(s):  
Panagiotis H. Tsarouhas

Purpose As overall equipment effectiveness (OEE) is a metric to estimate equipment effectiveness of production systems, the purpose of this paper is to identify strategic management tools and techniques based on OEE assessment of the ice cream production line. Design/methodology/approach This paper presents the collection and the analysis of data for ice cream production under real working conditions. The data cover a period of eight months. A framework process to improve the OEE of an automated production system was proposed. Six major stoppage losses, i.e. equipment failure, setup and adjustment, idling and minor stoppage, reduced speed, defects in the process, and reduced yield, were examined with the help of Pareto analysis. In addition, the actual availability (A), performance efficiency (PΕ) and quality rate (QR) measures, together with the complete OEE for each working day, week and month of the production line were shown. Findings The main goal of the study is to identify major stoppage losses, in order to examine and improve the overall equipment efficiency (OEE) of the ice cream production line through the application of an adequate management, i.e. TPM approach. Based on the obtained results, maintenance management strategy and production planning have been suggested to improve their maintenance procedures and the productivity as well. Originality/value The proposed method can be applied to each automated production system. The main benefits of this method are the improvement of productivity, quality enhancement of products, the reduction of sudden breakdowns and the cost of maintenance. Moreover, the analysis provides a useful perspective and helps managers/engineers make better decisions on the operations management of the line, and suggestions for improvement were proposed and will be implemented accordingly.


2020 ◽  
Vol 18 (1) ◽  
pp. 106-121
Author(s):  
Rubel Ahammed ◽  
Md. Zahid Hasan

Purpose Success and business reputation depend upon the quality of products where product quality depends upon the capability of a process, yield value and sigma score, etc. Poor quality of ceiling fan and mass rejection from quality check resulted in an alarming amount of cost for rework. As a result, the fulfillment of the production target was getting difficult day by day. The main purpose of this research is to identify the crucial causes for humming noise of ceiling fans and control it to a tolerable level so that maximum quality can be achieved. Design/methodology/approach The poor quality of ceiling fans was determined from the Pareto analysis of the define, measure, analyze, improve and control model which was humming noise during running and further actions were undertaken regarding the reduction of the humming noise. Project charter was formed before initiating the measure phase to study the suppliers, inputs, processes, outputs and customers diagram with process parameters and existing noise data were collected from random samples to determine the rolled throughput yield (94.95% existing) and existing sigma score which value of 3.14 and also the poor value (1.05) of process potential index implied that the process condition was below standard (<1.33) and need to be improved badly. Then root causes analysis and relationship diagram was prepared to identify the possible causes and with the design of experiments and correlation analysis, it was clear that the air gap between the stator and rotor was the main culprit behind the humming noise. Findings The minimum value of air gap was determined from boxplot analysis which was 0.2 mm–0.225 mm and the corresponding mean, the minimum and maximum value of sound level in dB (37.5–40.3 dB) for 0.225 mm air gap with the watt consumption (83 w) from the hypothesis test for the corresponding air gap. Finally, the updated sigma score and process capability analysis were performed with control charts to show the comparison after applying the DMAIC-six sigma methodology. The final sigma score was 5.1 which indicates a significant improvement of the process with the capability of saving US$23,438/year caused by the poor quality of ceiling fans. Practical implications Only quantitative values of the causes behind the humming noise were possible to identify. Other trivial many causes elimination might improve the sigma score closer to 6.00. The final sigma score that was achieved from this research was sustainable. Originality/value A structural approach with proper data analysis and application of various tools to detect the actual cause behind the humming noise of ceiling fans with numerical value has not been found in any literature. This research study can be a valuable asset for ceiling fan mass producers.


2018 ◽  
Vol 35 (5) ◽  
pp. 1034-1059 ◽  
Author(s):  
Pankaj Kumar ◽  
J. Maiti ◽  
Angappa Gunasekaran

Purpose Within the operations management literature, quality management (QM) has been one of the most popular research areas over the last few decades. The impact of QM systems on firm performance has been the subject of constant interest and challenge among researchers. Last such review was done in 2002 based on QM-related articles published between 1994 and 1999 and these were primarily on Total Quality Management (TQM). In the last 18 years, a large number of empirical studies have been attempted to investigate QM system-performance relationships in different contexts, covering not only TQM but also other QM systems such as ISO 9001, Total Productive Maintenance (TPM), Lean Manufacturing, Theory of Constraints (TOC), and Six Sigma Continuous Improvement projects. The paper aims to discuss these issues. Design/methodology/approach Based on an extensive review of 263 papers published in 17 reputed journals during the period 2000 to 2017, this paper shows the reflections of QM systems with respect to study of different QM systems, type of research designs being used, performance categories and metrics being used, and application of tools/techniques. Findings The literature review has revealed several gaps in research in the area of QM and calls for research on: empirical longitudinal case studies; implementation of multiple QM systems; identification of leading indicators of firm’s performance; standardization of performance measures; safety, environment and health-related performance measures; the differences in the QM systems on firm’s performance for manufacturing vs service organizations; application of QM systems in developing countries including Asian countries; and impact of ISO 9001 QM system on firm’s performance. Originality/value The literature reviews in the past had considered only the TQM-related articles published in reputed journals and did not cover other QM systems such as TPM, TOC, Toyota Production System, Six Sigma, ISO 9001 QMS, etc., which have also been widely used in many organizations, more so in the last 15 years.


2019 ◽  
Vol 25 (3) ◽  
pp. 452-475 ◽  
Author(s):  
Panagiotis Tsarouhas

Purpose The purpose of this paper is to compute reliability, availability and maintainability (RAM) indices to measure and improve the performance of an automated croissant production line under real working conditions. Based on this study, the authors demonstrate how RAM analysis is very useful for deciding maintenance intervals and for planning and organizing the adequate maintenance strategy. Design/methodology/approach The present work is carried out by analyzing failure and repair data based on statistical techniques. Descriptive statistics of the failure and repair data at workstation and line level were carried out. Trend and serial correlation tests validated the assumption of independence and identical distribution of the failure data were conducted. Moreover, the reliability and maintainability of both the croissant production line and its workstations have been estimated at different mission times with their best fit distribution. Findings The main objectives of the applied method are to understand the nature of the failure patterns, and to estimate the reliability and maintainability characteristics of the croissant production system in precise quantitative terms. The analysis identifies the critical points of the production line that require further improvement through effective maintenance strategy. Originality/value This study is anticipated to serve as an illuminating effort in conducting a complete RAM analysis and its effect on the performance of the system that works under real conditions. The advantage of the methodology is the continuous monitoring of the production process through appropriate indices, the utilization of which leads to a continuous cycle of improvement.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Astha Sharma ◽  
Neeraj Bhanot ◽  
Ajay Gupta ◽  
Rajeev Trehan

PurposeThis 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/approachA 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.FindingsThe 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 implicationsThe 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/valueThe 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.


2016 ◽  
Vol 28 (5) ◽  
pp. 774-785 ◽  
Author(s):  
Vesna Spasojevic Brkic ◽  
Branislav Tomic

Purpose – Lean management and Six Sigma concepts are derived from two different points of view, but it is evident that the role of employees is crucial in both concepts. The purpose of this paper is to survey which employees’ behaviour dimensions can lead organization to better concepts integration and how Lean Six Sigma activity contributes to employees’ performance. Design/methodology/approach – Research methodology is designed to empirically check, on large sample of companies in multinational company supply chain, if employees’ factors are both predictor and response variables of Lean Six Sigma concept. To check stated hypothesis factor, reliability and multiple regression analysis are used. Findings – The first finding of this study is that reward system and training are significant predictors of Lean Six Sigma activities. The second part of findings shows that Lean Six Sigma dimensions, such as Define, Measure, Analyze, Improve, and Control/Define, Measure, Analyze, Design, and Validate, 5S and Kanban positively influences employees’ performance, described by employee satisfaction, absenteeism, salaries and benefits, employees’ commitment and employee turnover rate. Research limitations/implications – Poka-Yoke application is not found as a significant predictor of employees’ performance. Accordingly, to explore that interesting finding, possible future research topic is more detailed analysis of Poka-Yoke application in similar supply chains. A longitudinal analysis using structural equation is possible direction of future work, too. Practical implications – This survey answers the need for Lean and Six Sigma unified methodology achievement in soft factors area and gives applicable results for companies in supply chain that produces low-volume, high-complexity products. Originality/value – Original and valuable conclusion is that employees’ factors are both predictor and response variables of Lean Six Sigma concept application.


2017 ◽  
Vol 25 (1) ◽  
pp. 91-108 ◽  
Author(s):  
Paul G. LeMahieu ◽  
Lee E. Nordstrum ◽  
Elizabeth A. Cudney

Purpose This paper is one of seven in this volume that aims to elaborate different approaches to quality improvement in education. It delineates a methodology called Six Sigma. Design/methodology/approach The paper presents the origins, theoretical foundations, core principles and a case study demonstrating an application of Six Sigma in a school-community partnership in Milwaukee, Wisconsin. Findings The core principles underlying the approach are decreasing variability or unreliability in organizational work processes, eliminate waste or activity that does not add value to desired outcomes, identify defects and decrease their incidence, reduce the cost of work processes, and improve beneficiary/client satisfaction levels. The steps in this statistics-dependent method are design, measure, analyze, improve and control. Originality/value Few theoretical treatments and demonstration cases are currently available on commonly used models of quality improvement that might have potential value in improving education systems internationally. This paper fills this gap by elucidating one promising approach. The paper also derives value as it permits a comparison of the Six Sigma approach with other quality improvement approaches treated in this volume.


2019 ◽  
Vol 16 (4) ◽  
pp. 594-624 ◽  
Author(s):  
Narottam Yadav ◽  
Kaliyan Mathiyazhagan ◽  
Krishna Kumar

PurposeThe purpose of this paper is to improve the yield of a particular model of a car windshield, as the organization faces losses due to poor performance and rejection.Design/methodology/approachThe Six Sigma DMAIC (define, measure, analyze, improve and control) methodology is used to reduce variation and defects in the process. It is a methodology based on data-driven and fact-based analysis to find out the root cause of the problem with the help of statistical analysis. A worst performing model is selected as a case study through the scoping tree. The preprocess, printing, bending and layup process defects are reduced by analyzing the potential causes and hypothesis testing.FindingsThis paper describes Six Sigma methodology in a glass manufacturing industry in India for automotive applications. The overall yield of a car windshield achieved 93.57 percent against the historical yield of 88.4 percent, resulting in saving 50 lacs per annum. Due to no rework or repairing in the glass, low first-time yield causes major losses. Process improvement through focused cross-functional team reduces variation in the process. Six Sigma improves profitability and reduces defects in the automotive glass manufacturing process.Research limitations/implicationsThis case study is applied in automotive glass manufacturing industries. For service and healthcare industries, a similar type of study can be performed. Further research on the common type of processor industry would be valuable.Practical implicationsThe case study can be used as a problem-solving methodology in manufacturing and service industries. The tools and techniques can be used in other manufacturing processes also. This paper is useful for industries, researchers and academics for understanding Six Sigma methodology and its practical implementation.Originality/valueThis case study is an attempt to solve automobile glass manufacturing problems through DMAIC approach. The paper is a real case study showing benefits of Six Sigma implementation in the manufacturing industry and saving an annual cost of 50 lacs due to rejections in the process.


2016 ◽  
Vol 7 (4) ◽  
pp. 406-429 ◽  
Author(s):  
Meryem Uluskan

Purpose As opposed to general literature reviews, by narrowing down the context only around the resources related to Six Sigma tools, this study aims to offer a strong discussion about Six Sigma toolbox which has a vital role in the success of Six Sigma. Design/methodology/approach Based on a comprehensive literature research, the most used tools; classification of tools; flow of tools with respect to define, measure, analyze, improve and control (DMAIC) steps; tools as critical success factors and reasons of ineffective use of tools are reviewed. To stay focused and not to diverge from the research aim, 60 articles which are suitable to the context and flow of the discussion are selected during the construction of the study. Findings The study provides a detailed and integrated review of Six Sigma articles about tools. The most used tools are listed from different perspectives and resources, and the role of these tools has been discussed. After a broad review, a more practical and combined classification of Six Sigma tools is proposed. Next, the issue of using which tools during which steps of DMAIC is systematically addressed. Finally, emergence of tools as a critical success factor and the gaps in the literature related to tools of Six Sigma are pointed out. Practical implications Addressing important statistics and the facts related to the tools of Six Sigma helps new practitioners in particular to build a strategic filter to select the most proper tools throughout their projects. Originality/value This study is unique in investigating only Six Sigma toolbox and providing a literature review on this subject.


2020 ◽  
Vol 17 (2) ◽  
pp. 73
Author(s):  
Katon Muhammad ◽  
Kukuh Winarso ◽  
Ida Lumintu

PT. XYZ is one of the animal feed companies which has some of the largest production units in Indonesia. This Feed Company has several brands of products on the market. The company's production line is indicated to have a problem, namely product defects. Defective products caused by the production process and also the process of storing raw materials and finished materials in the company. Related to the six sigma in it has a phase of define, measure, analyze, improve and control phases, is chosen to overcome the existing problems. From the define, measure and analyze phase, it is known that there are significant defects, namely defects with flea attributes in the production process, textures, lumps, and ticks in the inventory. From the results of the RPN assessment, it is known that tick defects on the production line are valued at 168, text 105 and ticks in the production process 90 so that from the results of the assessment the RPN is given recommendations for improvement with consideration of the highest RPN value. The recommended improvement recommendations are the installation of blowers and air temperature regulators in the company's storage section, conduct a design of experiment in stages to select the best raw materials by considering the quality problems of the products produced and thirdly, the improvement of the cleaning schedule in the cooler, spoting and also rotex on production machines to minimize the cause of defects.


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