What Is Six Sigma?

Six Sigma is a set of process improvement techniques designed to help organizations increase their performance, quality of products or services, profits, and company culture. In Six Sigma, improvement is achieved by identifying and removing defects’ causes and reducing all sources of variation in the processes. Some of the qualitative and quantitative tools included in the Six Sigma toolset are FMEA, process mapping, root cause analysis (RCA), 5 Whys, brainstorming, and others. 
 
The data-driven approach benefits companies by bringing increased customer satisfaction and greater profitability through minimizing defects and improving business processes. A Six Sigma project employs either the DMAIC or DMADV methodologies to improve existing products, services, and processes or create new ones. 
 
Thanks to the abundance of its process improvement techniques, the Six Sigma methodology is successfully applied for process management across large and mid-size organizations. Manufacturing, engineering, and healthcare industries widely utilize the quality improvement methodology. 

What Are the Six Sigma Principles? 

There are five key principles that make the Six Sigma quality improvement approach so effective. In the journey towards improvement, businesses applying the method need to put equal attention to the following principles. 

1. Customer focus. To improve quality using Six Sigma, always focus on the customer’s needs and expectations. 
2. Data collection. Understand how processes work through standardized data collection methods such as tools and graphical techniques. 
3. Root cause identification. Determine the root cause of problems based on clearly defined goals, accurate measurements, and in-depth analysis of real data. 
4. Variation elimination. Gradually remove all process variation as a way to eliminate defects. 
5. Team collaboration. Seek involvement and accountability from all team members through collaboration. 

What Are the Methodologies of Six Sigma? 

The most prominent methodologies of the Six Sigma approach are DMAIC and DMADV. Both methodologies are customer-focused, aim at reducing process variation while improving work operations. The framework’s main goal is to solve problems through the accumulation and analysis of data. 

• DMAIC: The acronym stands for Define, Measure, Analyze, Improve, Control. The methodology is the most widely adopted approach to problem-solving. Through the use of statistical tools such as FMEA or process mapping, Six Sigma practitioners apply the DMAIC to identify the causes of a problem and implement quality improvements. The framework is widely applied to improve existing processes.  
• DMADV: The acronym stands for Define, Measure, Analyze, Design, Verify. The methodology has a proactive nature and aims to prevent defects. DMADV is widely applied when a new process, product, or service is designed. 

While DMAIC methodology helps to improve existing processes, the DMADV approach is useful when new ones need to be devised. The former facilitates the elimination of problems and their root causes while the latter prevents their occurrence in the new process altogether. 

Which Industries Can Six Sigma be Used in? 

The Six Sigma approach is successfully applied to a wide range of industries. Pharmaceutical, airline, and manufacturing companies apply Six Sigma effectively to improve processes, increase customer satisfaction and profits, and reduce costs, process variability, and time for rework. 

The quality improvement approach has been initially adopted by large organizations from the manufacturing, engineering, and construction domains. However, Six Sigma includes a range of process improvement tools easily adaptable to small and mid-size companies. 

What Are the Benefits of Six Sigma? 

On top of the list of the benefits of a successful application of the Six Sigma approach are process improvement, variation identification, and defects elimination. Find some of the most prominent advantages of Six Sigma listed below. 

• Improvement of new and existing processes. 
• Improvement of customer satisfaction. 
• Increase in profitability. 
• Lower process variation. 
• Cost reduction. 
• Improved collaboration and employee morale. 
• Higher productivity. 

What Is the Criticism Point about Six Sigma? 

Abandonment is the leading cause for failing Six Sigma’s implementation. Improvement changes are often not sustained due to a lack of expert guidance and commitment. The key role of leadership participation in a Six Sigma process is crucial and can negatively impact employee morale, engagement, and overall improvement. Understanding Six Sigma and the benefits of its tools and techniques is another critical factor that can affect its successful implementation.  

What Are the Important Terms in Six Sigma? 

The terms most widely associated with the Six Sigma approach are explained below. 

1. Benchmark: Stable process metrics used by Six Sigma practitioners as a base criterion for further improvement. 
2. Black Belt: A Six Sigma certification that qualifies project leaders and mentors to execute large-scale projects and ensure changes are sustained. 
3. Customer Satisfaction: Satisfying the reasonable customer requirements and expectations. 
4. DMAIC: Methodology for identifying process problems and a way of addressing them to achieve process improvement. 
5. Hidden Factory: A set of activities in a process focused on eliminating root causes for unfavorable conditions such as quality or efficiency reduction. 
6. Quality Management: Process that seeks to ensure that products, services, or processes are consistent. 
7. Sigma Unit: Measures the standard deviation from the average of a process. 
8. Standardization: The process of standardizing or employing the same manner for performing a task, job, or process. 
9. Statistical Process Control: A statistical control chart for identifying the nature of variation in a process. 

What Are the Examples of Six Sigma?  

Six Sigma is equally adopted to improve the quality of products or services, streamline the work processes, and increase employee engagement. 

• Reducing the number of product defects before reaching the customers. 
• Reducing the cycle time from customer order placement to its delivery. 
• Lowering and eliminating byproduct wastage. 
• Supporting existing processes improvement. 
• Supporting organizational transformations. 
• Devising new product designs or processes. 
• Streamlining work processes. 

What Is the Definition of Six Sigma Certification? 

Six Sigma certification is a five-level training, and educational program developed and offered by some private organizations. The levels gained upon completing the certification reflect the level of knowledge and skills acquired, starting with White Belt, Yellow Belt, Green Belt, Black Belt, and Master Black Belt for the most advanced. A professional Six Sigma certification provides equal opportunities for engineers, analysts, and consultants alike.  

What Are the Belts of Six Sigma? 

Six Sigma training programs entitle you to five levels of certification depending on the acquired knowledge and skills. The five-tiered model is explained below. 

• White Belt: Means you have a basic understanding of the Six Sigma approach, its principles and methodologies. 
• Yellow Belt: Means that you have a deeper understanding of the Six Sigma philosophy and its most prominent adoption methodology - DMAIC. 
• Green Belt: Means you have introductory training in Six Sigma tools and techniques to problem-solving. 
• Black Belt: Means you have undergone in-depth training in Six Sigma tools and methodologies. 
• Master Black Belt: Means that you have the training and skills to lead a business transformation using the Six Sigma and DMAIC tools and techniques. 

White Belt certified professionals can participate in small quality improvement projects while Yellow Belts can better contribute to the project and assist managers in a Six Sigma project. Green Belt certification entitles professionals to act as project and team leaders while Balck Belt graduates handle large and long-term business endeavors. 

What Are the Tools of Six Sigma? 

Six Sigma tools are problem-solving tools or qualitative and quantitative techniques that support process improvement efforts. The most widely adopted statistical and graphic tools are mentioned below. 

1. DMAIC: The quality improvement strategy to define, measure, analyze, improve and control the process is an integral part of the Six Sigma approach. 
2. Value Stream Mapping: The Lean management method helps to improve work processes by visualizing all the steps in a delivery process, analyzing and improving them. 
3. Kaizen: The Kaizen methodology helps to improve continuously by making changes, analyzing results, adjusting, and repeating this improvement cycle until it becomes an intrinsic part of company culture. 
4. 5 Whys: One of the most effective Lean tools for root causes analysis helps to reveal the underlying causes of process impediments (including product defects) and is used to navigate quality improvement efforts. 
5. 5S: The Lean method seeks order, safety, and standardization of the working environment to reduce waste, streamline processes and optimize productivity leading to a quality work environment. 

What Is the History of Six Sigma? 

Developed in 1986 by Bill Smith and Mikel Harry from the Motorola company, the Six Sigma approach has originated as a goal for improving the manufacturing business process. Among the companies that first adopted the quality improvement method are also General Electric and Honeywell. 
 
Although it started as a set of empirical and statistical techniques for process improvement, the Six Sigma approach evolved to a multi-structured approach navigating business strategies. As a result, the principles of Six Sigma impact a variety of business aspects such as lowering defects, reducing costs and process variability, improving business operations and profitability.  

What Is the Connection between Lean and Six Sigma? 

Lean and Six Sigma are both process improvement approaches. The Lean methodology is focused on removing all waste from the work process and optimizing it. At the same time, Six Sigma helps identify and reduce all sources of process variability and defects. 
 
The synergy between the two improvement methods created the Lean Six Sigma approach as a standalone methodology for increasing performance through removing waste and reducing all process variation.  
 
The success of Lean Six Sigma relies on the deep understanding of the Lean mindset principles and the Six Sigma process logic. One of its most underlined advantages is that its implementation is facilitated by various available tools and techniques from the Lean and Six Sigma arsenal. These include Kanban, Kaizen, Value Stream Mapping, the 5S model, etc. 

What Is the Difference between Lean and Six Sigma? 

The difference between Lean and Six Sigma lies in how the two approaches reach their common goals - providing the best quality, improving processes, reducing costs, and increasing profitability.  
 
While Lean seeks to reduce waste from a process, Six Sigma reduces the process variation. In addition, the Lean concept employs less technical approaches to achieve its goals (Kaizen, 5S, VSM), while Six Sigma utilizes more scientific, statistical, and graphical tools (FMEA, control charts, process mapping). As such, the Lean philosophy encourages work standardization to achieve improvement, while the Six Sigma discipline relies on establishing control mechanisms.

In Summary

The Six Sigma guiding principles include:

1. Customer focus. 
2. Data collection. 
3. Root cause identification. 
4. Variation elimination.
5. Team collaboration.