VIETNAM NATIONAL UNIVERSITY – HO CHI MINH CITY INTERNATIONAL UNIVERSITY SCHOOL OF BUSINESS APPLY SIX SIGMA TO IMPROVE QUALITY Quality Management (BA018IU) FINAL REPORT Student’s Name: NGUYEN NGOC PHUONG TRINH (BABAIU19346) Lecturer: MR. DUONG VO NHI ANH Ho Chi Minh City, Vietnam 2023 TABLE OF CONTENTS I. INTRODUCTION ..............................................................................................................................................5 II. WHAT IS SIX SIGMA? ....................................................................................................................................5 III. CHARACTERISTICS .......................................................................................................................................5 IV. THE STATISTICAL BASIC OF 3.4 DPMO....................................................................................................6 V. IMPLEMENTING SIX SIGMA .......................................................................................................................7 1. WHAT ARE CALLED PROBLEMS IN SIX SIGMA? .............................................................................................7 2. PROJECT MANAGEMENT AND ORGANIZATION ..............................................................................................8 3. SELECTING SIX SIGMA PROJECTS .................................................................................................................9 VI. THE DMAIC IMPROVEMENT CYCLE ..................................................................................................... 11 1. DEFINE .......................................................................................................................................................... 11 2. MEASURE ...................................................................................................................................................... 15 3. ANALYZE ....................................................................................................................................................... 16 4. IMPROVE ....................................................................................................................................................... 18 5. CONTROL ...................................................................................................................................................... 19 VII. CASE OF AMAZON ................................................................................................................................... 20 VIII. CONCLUSION ............................................................................................................................................ 23 IX. REFERENCES ................................................................................................................................................. 24 TABLE OF FIGURES Figure 1. Defects per Million for ±3𝜎 vs. ±6𝜎 Figure 2. Theoretical Basis for Six Sigma Figure 3. Quality and Profitability Figure 4. Pareto Analysis of Computer Services Center Figure 5. Use of Pareto Diagrams for Progressive Analysis Figure 6. Example of CTQ tree Figure 7. Example of Cheet Sheet Figure 8. Example of Cause-and-Effect Diagrams Figure 9. Example of Control Chart Figure 10. Annual Net Revenue of Amazon from 2004 to 2020 TABLES Table 1. Tabulation of DPMO for Different Sigma Levels Table 2. Several types of individuals in Project Table 3. Problems and Causes in Computer Service Center I. Introduction Six Sigma is a methodology for process improvement developed by a scientist at Motorola in the 1980s. Six Sigma practitioners use statistics, financial analysis, and project management to achieve improved business functionality and better quality control by identifying and then correcting mistakes or defects in existing processes. Companies often use the Six Sigma model to increase efficiency and boost profits. The five phases of the Six Sigma method, known as DMAIC, are defining, measuring, analyzing, improving, and controlling. II. What is Six Sigma? Six Sigma is a process for developing and delivering virtually perfect products and services. The main idea behind Six Sigma is that if the number of “defects” in a process can be measured, then it can be systematically determined how to eliminate them and get as close to zero defects as possible. In Six Sigma, “as close to zero defects as possible” translates into a statistically based numerical goal of 3.4 defects per million opportunities (DPMO) or 99.99966% high-quality, which is the near elimination of defects from a process, product, or service. This is a goal far beyond the quality level at which most companies have traditionally operated. Through the reduction of variation in all processes (i.e., achieving the Six Sigma goal), the overall performance of the company will be improved and significant overall cost savings will be realized. Figure 1. Defects per Million for ±3𝜎 vs. ±6𝜎 For example, if 1 million passengers pass through the St. Louis Airport with checked baggage each month, a Six Sigma program for baggage handling will result in only 3.4 passengers with misplaced luggage. III. Characteristics The second TQM definition of Six Sigma is a program designed to reduce defects to help lower costs, save time, and improve customer satisfaction. Six Sigma is a comprehensive system— a strategy, a discipline, and a set of tools—for achieving and sustaining business success: (a) It focuses on total customer satisfaction. Six Sigma is a customer­focused, results­oriented approach to business improvement that integrates many traditional quality improvement tools and techniques that have been tested and validated over the years. Since Six Sigma is all about pleasing the customer, a very straightforward customer-oriented definition of quality can be employed—the ability to satisfy customer expectations. Six Sigma can be described as a business improvement approach that seeks to find and eliminate causes of defects and errors in manufacturing and service processes by focusing on outputs that are critical to customers and a clear financial return for the organization. (b) It is a discipline because it follows the formal Six Sigma Improvement Model known as DMAIC. This five-step process improvement model. (c) It is a set of seven tools: check sheets, scatter diagrams, cause-and-effect diagrams, Pareto charts, flowcharts, histograms, and statistical process control. IV. The statistical Basic of 3.4 DPMO Figure 2. Theoretical Basis for Six Sigma The etymology is based on the Greek symbol "sigma" or "σ," a statistical term for measuring process deviation from the process mean or target. Field failure data analyzed by Motorola discovered that Motorola’s processes drifted by an average of 1.5 standard deviations under normal control. Many common statistical process control plans use sample sizes that only allow detection of shifts of about two standard deviations. Thus, it would not be unusual for a process to drift this much and not be noticed. The allowance of a shift in the distribution is important because no process can be maintained in perfect control. The shaded distribution represents the natural variation of the process output. It is assumed to be normally distributed and centered on the nominal (target) specification. Recall that nearly 100 percent of the area under a normal distribution is within three standard deviations on either side of the mean. We also assume that the design tolerance has a 12-standard deviation spread so that the process capability index for the shaded distribution is Cp = 2.0, which represents excellent capability. A “six-sigma quality level” corresponds to a process variation equal to half of the design tolerance while allowing the mean to shift as much as 1.5 standard deviations from the target. Table 1. Tabulation of DPMO for Different Sigma Levels If the process has six Sigmas, three above and three below the mean, the defect rate is classified as "extremely low." Because if we calculate the tail area of one of the shifted curves beyond the specification limit (which is six standard deviations from the target—the basis for the name “six sigma”), we obtain 0.0000034, or 3.4 parts per million. V. Implementing Six Sigma 1. What are called Problems in Six Sigma? The first step in using Six Sigma is to select an appropriate problem; however, not every problem can be addressed using Six Sigma methodology. According to Kepner and Tregoe, a problem is a deviation between what should be happening and what actually is happening that is important enough to make someone think the deviation ought to be corrected. Research using more than a thousand applicable published cases suggests that virtually every instance of quality problemsolving falls into one of five categories. Each of these categories of problems requires different approaches and methodologies. Six Sigma methods are most applicable to conformance problems because the processes that create the problems can be easily identified, measured, analyzed, and changed. For efficiency problems, lean tools, are generally used. Unstructured performance problems require more creative approaches to solving them. For product design problems, special tools and methods are available. Process design problems may require a combination of many of these approaches. 2. Project Management and Organization Projects are the vehicles that are used to organize and to implement Six Sigma. Although projects are set up as temporary organization structures, their flexibility allows cross-functional teams to complete significant work in minimum time, if well managed. One of the challenges of implementing Six Sigma projects is to coordinate them with normal work activities. Some slack time, as well as physical and financial resources, must be allocated to project teams in order for them to achieve their objectives. Team members and project leaders cannot be expected to carry a full load of routine work and still participate fully and effectively on Six Sigma project teams. Projects fail for a variety of reasons, including not adhering to schedules, poor planning, and “scope creep” when the nature of the project gradually loses its focus and becomes unwieldy, mismatching of skills, and insufficient knowledge transfer. Being able to manage a large portfolio of projects, as would be found in Six Sigma environments, is vital to organizational success. Teams are vital to Six Sigma projects because of the interdisciplinary nature of such projects. Six Sigma projects require a diversity of skills that range from technical analysis, creative solution development, and implementation. Thus, Six Sigma teams not only address immediate problems, but also provide an environment for individual learning, management development, and career advancement. Six Sigma teams are comprised of several types of individuals: TYPES DESCRIPTION Champions Senior-level managers who promote and lead the deployment of Six Sigma in a significant area of the business. Champions understand the philosophy of Six Sigma, select projects, set objectives, allocate resources, and select and mentor teams. Champions own Six Sigma projects and are responsible for their completion and results; typically they also own the process that the project is focused on improving. More importantly, champions work toward removing barriers—organizational, financial, personal—that might inhibit the successful implementation of a Six Sigma project. Master Black Belts Full-time Six Sigma experts who are responsible for Six Sigma strategy, training, mentoring, deployment, and results. Master Black Belts are highly trained in how to use Six Sigma tools and methods and provide advanced technical expertise. They work across the organization to develop and coach teams, conduct training, and lead change, but are typically not members of Six Sigma project teams. Black Belt Fully trained Six Sigma experts with extensive technical training who perform much of the technical analysis required in Six Sigma projects, usually on a full-time basis. They have advanced knowledge of tools and DMAIC methods, and often act as project team leaders. They also mentor and develop Green Belts. Thus, Black Belts need good leadership and communication skills. As such, Black Belts are often targeted by the organization as future business leaders. Green Belts Functional employees who are trained in introductory Six Sigma tools and methodology and work on projects on a part-time basis, assisting Black Belts while developing their own knowledge and expertise. Typically, one of the requirements for receiving a Green Belt designation is to successfully complete a Six Sigma project. Successful Green Belts are often promoted to Black Belts. Yellow Belt Individuals from various functional areas who support specific projects. Basic understanding of the Six Sigma methodology and the tools within the DMAIC problem-solving process. Role is to be an effective team member on process improvement project teams. Table 2. Several types of individuals in Project 3. Selecting Six Sigma Projects There are two ways for an organization to generate Six Sigma projects: (a) Top-down. Top-down projects generally are tied to business strategy and are aligned with customer needs. Their major weakness is that they are often too broad in scope to be completed in a timely manner. In addition, top managers may underestimate the cost and overestimate the capabilities of the team or teams to which the project is assigned. (b) Bottom-up. In a bottom-up approach, Black Belts (or Master Black Belts) choose the projects that are well-suited to the capabilities of teams. However, a major drawback of this approach is that the projects may not be tied closely to strategic concerns of top management, thus receiving little support and low recognition from the top. Perhaps the best way to ensure success is for executive champions, who understand the impact of projects from a strategic perspective, to work closely with the technical experts in choosing the most relevant projects that fit within the capabilities of Six Sigma teams. A Six Sigma project might span an entire division or be as narrow as a single production operation. Factors that should be considered when selecting Six Sigma projects include the following: (a) Financial impact, as measured by cost savings, increased revenues, or return on investment. The financial value of a successful project can be difficult to quantify. Lower costs associated with poor quality, such as scrap, rework, excessive cycle times, delays, and lost customers, add to the bottom line. Traditionally, measuring reductions in qualityrelated costs through cost of quality analysis was the principal method of documenting the benefits of improvement initiatives. However, this approach only focused on internal benefits. Six Sigma has placed more attention on external benefits related to increases in revenues associated with improved quality and customer satisfaction. The foundation for the approach stems from the model shown in Figure 1.3 relating quality and profitability, which proposes that quality improvement leads to financial returns through improvements in customer satisfaction and loyalty. Figure 3. Quality and Profitability (b) Impacts on customers and organizational effectiveness. Six Sigma projects should lead to improved customer satisfaction and organizational performance. Such improvements can lead directly to higher sales or market share, thus providing financial justification for selecting a project. (c) Probability of success. At the outset of a Six Sigma initiative, it is beneficial to pick the projects that are easy to accomplish, or even can be completed by a single individual in order to show early successes. This visible success helps to build momentum and support for future projects. (d) Impact on employees. Six Sigma projects should fit within the capabilities of the people and teams that work on them. Many indirect benefits accrue. The training received as Green or Black Belts improves employee and organizational knowledge, and participating in Six Sigma projects improves team and leadership skills. Six Sigma can motivate employees to innovate and improve their work environment, and ultimately their satisfaction on the job and personal self-esteem. Many projects offer opportunities to reduce frustration with inadequate work processes or to provide increased value to customers; these types of projects are certainly important candidates for selection. (e) Fit to strategy and competitive advantage. It becomes important to be able to differentiate between, and to estimate fairly accurately, the differences in resources required to bring a difference project to a successful conclusion. VI. The DMAIC Improvement Cycle The five-step DMAIC improvement cycle is an important element of Six Sigma, listing the sequence of steps necessary to drive process improvement and through continuously using, systematically determined how to eliminate them and get as close to zero defects as possible. The cycle can be applied to any process or project, both in services and manufacturing firms. Using the DMAIC improvement cycle allows the firm to continuously monitor and improve processes that are keys to customer satisfaction. By concentrating on these key processes and the critical-toquality (CTQ) characteristics, firms can make large and radical improvements in processes, products, and customer satisfaction. Each of the steps is described below: 1. Define The problem is defined, including who the customers are and what they want, to determine what needs to improve. It is important to know which quality attributes are most important to the customer, what the defects are, and what the improved process can deliver. There are many tools to use in Define phase such as: Project Charter, Cost of Quality Analysis, Pareto Analysis, High-Level Process Mapping, SIPOC, Operational Definition, Voice of Customers, Critical to Satisfactions, etc. For example, one useful tool to help identify the most important issue among a mess of symptoms is Pareto analysis. Pareto analysis clearly separates the vital few from the trivial many and provides direction for selecting projects for improvement because a Pareto distribution is one in which the characteristics observed are ordered from largest frequency to smallest. Imaging, Jack has taken over a failing computer service center, with a host of problems that need resolving. His objective is to increase overall customer satisfaction. He decides to carry out a Pareto Analysis to assess and prioritize the biggest issues facing the center. He starts by listing these (see the Problem column in the table, below). He then identifies the underlying causes behind each (see the Causes column). Finally, he scores each item by the number of customer complaints that each has received (see the Score column). Items Problem Cause Score 1 Phones aren't answered quickly Too few customer enough. service staff. 15 2 Staff seem distracted and under Too few customer pressure. service staff. 6 3 Engineers aren't well organized Poor organization and and often need to book second preparation. visits to bring extra parts. 4 4 Engineers don't know what time they'll arrive. This means that Poor organization and customers may have to be in all preparation. day for an engineer to visit. 2 5 Customer service staff don't always seem to know what Lack of training. they're doing. 30 6 Customers are often booked in for an appointment with an engineer, only to discover that the Lack of training. issue could have been solved on the phone. 21 Table 3. Problems and Causes in Computer Service Center Jack uses his analysis to group problems together by cause, then adds up the scores for each group identified. He is now able to order the main causes affecting the center, starting with the one that has attracted the highest number of customer complaints: Lack of training (items 5 and 6) – 51 complaints. Too few service center staff (items 1 and 2) – 21 complaints. Poor organization and preparation (items 3 and 4) – 6 complaints. Figure 4. Pareto Analysis of Computer Services Center Thus, the business will benefit most from giving staff more training, so Jack should tackle this first. He could also look to increase the number of staff in the call center. However, it's possible that this won't be necessary – the provision of further training may help to reduce customer complaints and increase staff productivity. Jack's Pareto Analysis has enabled him to quickly identify the areas of the business that face the biggest challenges, so he can focus his efforts where they are needed most and prioritize issues that will provide the biggest payoff to the business. This will likely save him a great deal of time and money that he might otherwise have spent trying to fix a range of different issues, some of which may have provided very little benefit. Moreover, Pareto diagrams help analysts to progressively focus in on the most appropriate problems. At each step, the Pareto diagram stratifies the data to more detailed levels, eventually isolating the most significant issues. Figure 5. Use of Pareto Diagrams for Progressive Analysis 2. Measure In Measure phase, it prepare a data-collection plan from current process to understand and quantify the baseline performance of the process. Determine what to measure for each process gap and how to measure it. The measure phase of the DMAIC process focuses on understanding process performance and collecting the data necessary for analysis. Six Sigma uses the notion of a function in mathematics to portray the relationship between process performance and customer value: 𝑌 = 𝑓(𝑋), where Y is the set of CTQs and X represents the set of critical input variables that influence Y. Understanding these relationships also helps in defining the experiments that need to be conducted to confirm how input variables affect response variables. In addition, it sets the stage for the Control phase by defining those factors that requiring monitoring and control. One example of CTQ tree, a grocery store collected customer feedback to identify business improvement opportunities. From the data, they have realized that most customers are looking for an online option to place an order without being at the store to buy the groceries. Use the CTQ Tree method to translate customer needs into specific, measurable, and actionable performance requirements. Figure 6. Example of CTQ tree One must first ask some basic questions related to measurement: (a) (b) (c) (d) (e) What questions are we trying to answer? What type of data will we need to answer the question? Where can we find the data? Who can provide the data? How can we collect the data with minimum effort and with minimum chance of error? In addition, measurement system analysis is vital to ensure that manufacturing-based data used in a Six Sigma project is valid and reliable. Some tools are used in Measure phase such as Data Collection Plan, Normallity Test, Run Charts, Check Sheets, Descriptive Statistics, Measurement System Evaluation, Process Capability Analysis, Benchmarking, etc. Example shows that calls made to wrong number are highest cause of telephone interruptions in radiology department. Check sheets are special types of data collection forms in which the results may be interpreted on the form directly without additional processing. Figure 7. Example of Cheet Sheet 3. Analyze In Analyze phase, it perform a process analysis using the performance data collected. The data are analyzed in order to identify potential causes of the problem and validate them to obtain the root causes. The Analyze phase of DMAIC focuses on why defects, errors, or excessive variation occur, which often result from one or more of the following: (a) A lack of knowledge about how a process works, which is particularly critical if different people perform the process. Such lack of knowledge results in inconsistency and increased variation in outputs. (b) A lack of knowledge about how a process should work, including understanding customer expectations and the goal of the process (c) A lack of control of materials and equipment used in a process (d) Inadvertent errors in performing work (e) Waste and complexity, which manifest themselves in many ways, such as unnecessary steps in a process and excess inventories (f) Hasty design and production of parts and assemblies; poor design specifications; inadequate testing of incoming materials and prototypes (g) Failure to understand the capability of a process to meet specifications (h) Lack of training (i) Poor instrument calibration and testing (j) Inadequate environmental characteristics such as light, temperature, and noise Common tools are use in Analysis phase such as Scatter Diagrams, Detailed Process Mapping, Statistical Inference, Cause-and-Effect Diagrams, Failure Mode and Effects Analysis, Root Cause Analysis, Gemba Investigation, Hypothesis Test etc. The following graphic is an example of a fishbone diagram with the problem "Shorted Motor Coils Causing 23% Failure Rate on Cycle Destruct Test." A cause-and-effect diagram is a simple graphical method for presenting a chain of causes and effects and for sorting out causes and organizing relationships between variables. Cause-and-effect diagrams are useful in assisting teams to generate ideas for problem causes and, in turn, serves as a basis for identify solutions. At the end of the horizontal line, a problem is listed. Each branch pointing into the main stem represents a possible cause. Branches pointing to the causes are contributors to those causes. Cause-and-effect diagrams are constructed in a brainstorming type of atmosphere. Everyone can get involved and feel they are an important part of the problem-solving process. Usually small groups drawn from operations or management work with a trained and experienced facilitator. The facilitator guides attention to discussion of the problem and its causes, not opinions. As a group technique, the cause-and-effect method requires significant interaction between group members. The facilitator who listens carefully to the participants can capture the important ideas. A group can often be more effective by thinking of the problem broadly and considering environmental factors, political factors, employee issues, and even government policies, if appropriate. Figure 8. Example of Cause-and-Effect Diagrams 4. Improve In Improve phase, it generate solutions and formulate an implementation roadmap based on the identified solution which design an improvement plan, then remove the causes of process variation by implementing the improvement plan. This will require modifying, redesigning, or reengineering the process. Document the improvement and confirm that process gaps have been significantly reduced or eliminated. Checklists are often used as a guide for generating ideas. Osborn proposed about 75 fundamental questions based on the following principles to spawn new ideas: (a) (b) (c) (d) (e) (f) (g) (h) (i) Put to other uses Adapt Modify Magnify Minify Substitute Rearrange Reverse Combine Therefore, improving may be use Design of Experiments, Mistake Proofind, Lean Production, Deming cycle, or Seven Management and Planning Tools, Prioritisation matrix, Implementation Roadmap, Action Steps, etc., to improve process. Moreover, problem solutions often entail technical or organizational changes. Often some sort of decision or scoring model is used to assess possible solutions against important criteria such as cost, time, quality improvement potential, resources required, effects on supervisors and workers, and barriers to implementation such as resistance to change or organizational culture. To implement a solution effectively, responsibility must be assigned to a person or a group who will follow through on what must be done as well as where, when, and how it will be done. One example of How to Improve Sales for a Company by applying PDCA. PDCA can be implemented in the following ways for checking and improving sales of a company: 5. Plan – Identify the whys as to sales being down and how to improve the same. Do – Implement solutions in a small way. Check – Set benchmarks to check improvements in new processes against the old. Act – Choose the right solution and implement worldwide. Control If the process is operating at the desired level of performance, it is monitored to make sure the improvement is sustained and no unexpected and undesirable changes occur. Design and use statistical process control charts to continuously monitor, control and sustain the improvement changes. Controls might be as simple as using checklists or periodic status reviews to ensure that proper procedures are followed, or employing a control chart or a run chart (a line chart of time series data without control limits) or standard operating procedures, poka-yoke to monitor the performance of key measures. When performance gaps are once again identified, repeat steps 1– 5. For example, Suppose Arena Electronics Ltd. is a company that manufactures televisions. Sam, the quality control manager in the company, wanted to track the number of dead pixels on 55-inch LCD screens. The technicians in the company recorded the number of dead pixels for each screen. Each subgroup comprises a different number of screens. John used a chart to track the average number of dead pixels per screen. This is an example of a control chart. Figure 9. Example of Control Chart VII.Case of Amazon Amazon is such a shining example of six sigma, in fact, Amazon uses lean six sigma, but in this case, to emphasize the applicability of DMAIC, only refers to the six sigma strategy in general that the company would certainly serve well as an inspiration for your own business. Six sigma is rarely mentioned by name in Amazon’s annual reports and press releases, yet the methodology is entrenched in the culture of company. Beginning in 1994 as a retailer selling one particular product line, it gradually morphed into a product line, an entertainment hub and a symbol whose sum is greater than its respective parts. When Amazon.com was first launched on July 5,1994 by Jeff Bezos, it was an online bookstore which others thought doomed to fail. Many critics thought Jeff Bezos crazy when stocked his online bookshop with one million book titles. The e-business has since expanded to sell music, electronics, videos, pharmaceuticals, pet supplies, home improvement products and groceries. Not to mention its evolution as a market place for Third party sellers, A supply chain management expert for business customers and Amazon Web Services (AWS) for networking infrastructure. Over the 2000-2010 decade, Amazon has developed a customer base of around 30 million people. Ever since beginning life as an online bookstore, Amazon.com has drastically expanded its product range. They have even implemented innovative practices like same-day delivery, set to reach new heights for efficiency with automated drone delivery. Yet that sum needs instrumentation in order to operate efficiently. That instrumentation needs to understand how those constituent parts interact fully and comprehensively. And those constituent parts need to understand just how their respective roles affect the greater whole of that sum. That instrumentation is the key to understanding Amazon's metrics. It's called the DMAIC model and it's part of a well established business philosophy also known as Six Sigma. It's a strategy that's driven by data. And it's responsible in no small part for Amazon's orchestrated disruption. Six sigma methodology is in the culture of company. Six sigma is part of the operational excellence program that began in 1999 when Jeff Wilke joined Amazon as VP of operations. He came from Allied signal and his background in six sigma made him the perfect choice to drive efficiencies in operations because in 1999 Annual Report of Amazon.com, Amazon stated that “Operational excellence: To us, operational excellence implies two things: delivery continuous improvement in customer experience and driving productivity, margin, efficiency, and asset velocity across all over businesses.” 1. Define The business model of a flywheel isn't necessarily exclusive to Amazon. But they perfected it to such a degree that it's become one of the most referenced examples of how retail growth maintains its own momentum. In Amazon's case, growth is generated by six specific factors: lower cost structure, lower prices, customer experience, traffic, sellers and selection. Amazon identifies areas within its operations or processes that require improvement. These areas could be related to order fulfillment, inventory management, logistics, customer service, or any other critical aspect of their business. The goals are defined, and specific metrics are established to measure the current performance. The concept of six sigma was developed as a way to cut costs in business manufacturing processes. While each influences one another, customer experience is the sustaining momentum of that flywheel. And customer-centricity is the very foundation of Amazon's success. Amazon defines itself and its own growth by the hallmark of customer experience. 2. Measure Data is collected and analyzed to quantify the performance of the identified processes. Amazon uses various performance metrics and KPIs to evaluate the efficiency and effectiveness of their operations. They may use customer feedback, order processing times, defect rates, and other relevant data to gain insights into the current state of their processes. 3. Analyze The collected data is thoroughly analyzed to identify the root causes of any inefficiencies or issues. Amazon employs statistical tools and techniques to understand the patterns and relationships between variables impacting their processes. By using six sigma methods, Amazon was able to reduce variation by actively seeking it out using DMAIC, Root Cause Analysis, and similar tools. They reduced waste by cutting spending, eliminating non-value- adding process stages, and cultivating a Kaizen-based company culture. The analysis helps them pinpoint the primary drivers of problems and areas that require improvement. 4. Improve Based on the analysis, Amazon devises and implements improvement strategies. They introduce process changes, operational enhancements, or technology solutions to address the root causes identified in the previous step. The improvements are carefully tested and validated before being fully integrated into their operations. Amazon's retail model subsequently changed the game for good. They adapted to a new and virtually unexplored environment and came up with an entirely unique business proposition: customer-centricity. 5. Control In this final step, Amazon sets up controls and monitoring mechanisms to ensure that the improvements are sustained over time. They establish processes to track ongoing performance and regularly review the results to identify any signs of deterioration. By maintaining a focus on continuous improvement, Amazon can sustain the benefits achieved through the DMAIC process. Figure 10. Annual Net Revenue of Amazon from 2004 to 2020 Using Six Sigma they have made rapid progress in becoming a global online retailer. With a culture focused on continuous improvement and greatest efficiency possible, Amazon has taken over the world. In doing so; the impact of Six Sigma on Amazon.com can be seen through the statistical representation. Six Sigma is more than just a methodology for improving an organization’s quality. Most people don’t understand the nuances and complexities of Six Sigma beyond its well-known uses. Those who aren’t quite au fait on the subject may see Six Sigma as a simple improvement strategy. But they often don’t question how it improves businesses or what it needs to function. In truth, data drives Six Sigma’s success. Without sufficient data, you simply cannot make decisions without data to support and justify them. Six Sigma’s data-driven nature derives from the six standard deviations practitioners use to keep defects in check. Like Six Sigma, data drives everything for Amazon. From the types of purchases, customers make online to how people use their technology. Moreover, Amazon uses various metrics to constantly harvest data that shed light on areas for improvement and opportunities for expansion. For Amazon, data isn’t just a means to improve customer experience. It’s a way of life. Amazon has always been researching, innovating, and implementing bold supply chains strategies. In 2004, Amazon’s annual revenue was just under $7 billion. According to Statista, by 2018, its annual revenue reached almost $233 billion. Amazon is the fastest company to reach $100 billion in sales revenue, taking only 20 years. From its inception, Amazon has grown approximately 20% per year. It grew from 30% from 2018 to 2019. Currently, it enjoys more than 13% of gross global e-commerce sales. In short, Amazon is devoted to excellent customer service and experience. Before they revamped their business operations at the start of the millennium, they were indistinguishable from any other online bookstore. Using Six Sigma they have made rapid progress in becoming a global online retailer. With a culture focused on continuous improvement and greatest efficiency possible, Amazon has taken over the world. In doing so, they have emerged as a technology giant to stand alongside the likes of Apple or Microsoft. VIII. Conclusion In conclusion, Six Sigma can be a powerful and strategic methodology to consistently measure results, which can then become a new baseline for improved performance, ultimately getting you closer and closer to operational excellence. By utilizing Six Sigma, the project management organization uses a disciplined, data-driven approach to minimize or eliminate defects in any process. This process can be used inmanufacturing, engineering, leadership, and any role where there is a specific process. Those organizations that can embrace this philosophy across their enterprise can effectively transform their manufacturing operations into a world class, unstoppable leader. IX. References Burghate, Mukul. (2021). Lean 10.6084/m9.figshare.14253281. Six Sigma (6) Case Study: Amazon.com. Sharma, P. (2017). Six sigma-a case study of amazon. Com. International Journal of Research in Management, Economics and Commerce, 7(8), 131-135.