November 25, 2018

what is six sigma concept - dmaic

The concept of six sigma was introduced for the very first time in the 70s. A senior executive at Motorola queried the inconsistent quality of the company’s products. As a result, the system was developed to improve quality while reducing costs. In the mid-80s, the six sigma concept was fully launched and became popular. So, what is six sigma concept? what is six sigma concept - dmaic

Today, six sigma has evolved from the manufacturing industry to other industries. Almost every industry employs six sigma concepts to improve their operations. Six Sigma aims at identifying and eliminating errors that cause defects in a process, product or service. This concept is employed by management for quality improvements.

Besides, implementing six sigma concepts is not only beneficial to the organisation but its employees and customers as well. Quality improvements eliminate the waste of time. Therefore, employees are able to manage their time properly. In turn, this boosts customer satisfaction and loyalty. In addition, six sigma improves the organization’s profitability.

By reading this article, you will be able to:

  • Explain the six sigma concept.
  • Define six sigma.
  • Describe six sigma processes.

What is Six Sigma Concept?

Sigma is one of the letters in the Greek alphabet. In statistics, sigma is used as a symbol to represent standard deviation from the mean.

In the 1920s, Walter Shewhart suggested that three sigma from the mean indicates a critical point. Also, it shows that there are too many defects in the process that require correction.

For many years, organizations adopted this philosophy until Bill Smith came up with the six sigma concept. The six sigma concept lays emphasis on quality. It aims at eliminating errors that exist in a process, product or service. Thereby, enhancing process, product or service improvements. In addition, the six sigma concept ensures customer satisfaction and loyalty.

Benefits of Six Sigma Concept

The six sigma concept focuses on reducing variation. Since sigma is derived from standard deviation, the concept of six sigma seeks to reduce deviation to the barest minimum. When an organization reduces variation in its products, processes or services, it is able to achieve consistency. Consistency leads to quality.

Thus, if an organization’s process is operating at a Sigma 1, it indicates that most of its products are defective. A more practical situation may be to operate at a Sigma 3 or 4. However, an ideal situation would be to operate at a sigma 6. For example, if the organization produces a million goods, at a Sigma 3, 93.32% or more of the organization’s products are non-defective. This will result in 66,800 defective products. At sigma 4, 99.38% of the organization’s products are non-defective. This leads to 6,210 defective products. Whereas, at a Sigma 6, 99.99% of the organization’s products are non-defective. This will result in only 3.4 defective products.

The concept of six sigma is to improve productivity and profitability. It aims at reducing defects and waste, improving time management and decreasing cycle time. Six Sigma concept offers an organized method of solving problems. It ensures that employees are trained intensively. As such, the concept of six sigma can be applied to any type of business.

What Six Sigma Concept is NOT

Furthermore, the concept of six sigma does not focus entirely on customer loyalty but quality. It is based on the philosophy that the ideal way to cut down cost is by reducing defects. This is because defects lead to a waste of time, resources and money. As such, defects are expensive to manage.

Nevertheless, the six sigma concept did not originate to benefit organizations alone. It also emphasises on customer needs, expectations and satisfaction. Since the customers are the final consumers, this concept ensures that organizations tailor all forms of improvement to suit their customer’s preferences.

In the same vein, the six sigma concept does not depend on measuring output and establishing controls as some conventional methods do. Instead, it aims at eliminating defects. As a result, this concept involves the customer in the process of change. The six sigma concept ensures that organizations out measures in place in order to understand their customer’s expectations.

The six sigma concept borders around three methods: DMAIC, process management and Design for six sigma (DFSS). DMAIC is an acronym for Define, Measure, Analyse, Improve and Control. Process management involves structuring organizational processes in a way that helps them achieve their goals. On the other hand, Design for Six Sigma is another name for DMADV. DMADV stands for Define, Measure, Analyse, Design and Verify. This method is employed when designing new products.

Six Sigma Definition

Six Sigma is a management tool that aims at eliminating defects and reducing variation. It is a management philosophy that makes the most effective use of statistical tools, rather than guesswork. Because of the versatility of the method, its definition may vary.

Furthermore, it employs statistical analysis to boost quality and efficiency. Six Sigma concept is based on the idea that identifying defects ultimately leads to perfection. When defects are identified in a process, product or service, they can easily be eliminated. As a result, quality improvement is achieved.

In today’s technological age, information spreads like wildfire. Whenever something happens, people in other parts of the world get to know in a matter of minutes. As such, it is paramount for businesses to uphold a reputation of high quality. A slight insignificant deviation from quality might ruin an organization’s reputation globally. This is where six sigma really helps.

In the 1980s, companies like Honeywell and Motorola implemented the six sigma concept to improve their processes. By the 1990s, other companies adopted the six sigma methodology. Today, any organization can employ six sigma to improve its operations. Likewise, six sigma helps organizations to improve the quality of their products as well as boost customer satisfaction and loyalty.

Pros of six sigma

Six sigma helps to measure process quality. The main aim of six sigma is to improve the final product by eradicating all forms of defects in the process. However, it is data driven so it depends heavily on management strategies. The goal of the six sigma concept is to work smarter, not harder. It uses data collated to improve the process, reduce/ eliminate mistakes and increase sigma rating.

Cons of six sigma

Nonetheless, six sigma is very rigorous to implement. It involves a somewhat difficult process that takes a long time to achieve. By so doing, it ensures that everyone involved in the process is following closely enough to realise the value of six sigma. For this reason, six sigma is performed by a selected team of trained and certified professionals.

Six Sigma certifications

Unlike other professional certifications, six sigma certifications are available from various certification bodies. The American Society of Quality (ASQ) and the International Association for Six Sigma Certification (IASSC) are some examples of six sigma certification bodies. Notwithstanding, it is the responsibility of individuals desiring certification or their employers to research and compare programs before engaging.

Six Sigma professionals are placed ranked based on their certifications and roles in six sigma implementation. This ranking is known as six sigma belts. The levels of six sigma belts are white belt, yellow belt, green belt, black belt and master black belt. They conduct projects and implement improvements at the project level of six sigma implementation. On the other hand, six sigma executives and champions provide administrative support during project implementation.

Moreover, organizations need to employ the six sigma concept because the business environment is dynamic. Six Sigma helps to develop well-organised processes while achieving high-quality products. Furthermore, it ensures that organizations are able to realize their goals.

Six Sigma Process

The six sigma concept combines a number of striking tools in implementing improvements. Basically, it employs a blend of statistical tools and data analysis. Six Sigma process also combines tools like process mapping and design with other improvement techniques that help to achieve the required impact.

For example, brainstorming is an important technique used in six sigma process to generate ideas. Generally, organizations apply this technique when defining a new process, launching a new product or increasing sales. However, brainstorming in the six sigma process is more complex. It requires much more than critical thinking or the free flow of ideas. Brainstorming is essential for generating information for other six sigma techniques like 5Why, FMEA, Fault Tree Analysis and the likes.


FMEA is an acronym for Failure Mode Effects Analysis. This six sigma technique is also known as potential failure and effects analysis or Failure Modes, Effects and Criticality Analysis (FMECA). It is used to detect likely errors that might occur in a product, service, process or design. There are two types of FMEA; they are Process FMEA (PFMEA) and Design FMEA (DFMEA). FMEA can be used in the Analyse or Design phase of DMAIC, depending on what it intends to achieve.


On the other hand, 5Why is a six sigma technique that helps to ascertain the root cause of defects by asking “why” questions. Similarly, Fault Tree Analysis (FTA) is a technique used in the six sigma process to identify potential causes of errors, before they occur. This technique employs statistical and analytical strategies to determine the highest causes of errors.

Voice of the customer

In addition, the voice of the customer is a proactive technique used to gather feedback from customers. It is applied to both the internal and external customers of an organization. This technique is used in the six sigma process to understand customer’s needs, expectations and experiences. By so doing, process improvements can be tailored in a way that meets and exceeds customer’s expectations.

The best way to know the “voice of the customer” is through direct conversations and interviews. Group discussions and surveys are other methods of determining the voice of the customer.


Also, SIPOC is a technique used in six sigma processes to understand the scope and function of the process under review. SIPOC is an acronym for Suppliers – Inputs – Process – Outputs – Customers. These elements are connected in one way or the other. First of all, suppliers provide inputs for the process. These inputs are in the form of resources, services or information. Secondly, the process requires inputs to generate outputs. The process is a flow of activities that modify the inputs to produce valuable outputs that give value to customers. Thirdly, outputs are the end products, service or information. Finally, customers are the end-users of the outputs generated by the process. Usually, SIPOC technique is applied during the Define phase of DMAIC.

Process maps

These are used in the six sigma process to outline an existing process in a simplified way. Process maps require two steps. One step describes the process as the team thinks it is, while the other describes the process as the team desires it to be. Therefore, a process map can be defined as a think flow chart. This is one of the most common techniques used in six sigma process.


In summary, six sigma concept is a technique used by management to reduce and/ or eradicate defects and variations. Although variations exist in every process, this concept helps to reduce it in a way that it becomes insignificant. This is because variations lead to defects. Defects hinder consistency and consistency is the key to achieving quality.

Besides, defects result in waste. When defects exist in a process, it leads to waste of time, resources and money. However, if these wastes are taken away, employees can manage their time effectively. Likewise, the organization achieves optimum results.

In addition, the concept of six sigma does not benefit the organization alone. this concept is also beneficial to the customers, as they are the end-users of the organization’s products. Hence, six sigma emphasises on meeting and exceeding the expectations and needs of customers.

Furthermore, the six sigma concept involves lots of statistical and data analysis. Therefore, six sigma processes use a number of techniques in implementing quality improvements. Voice of the customer, brainstorming and SIPOC are a few examples.


While this is an attempt to answer the question “What is six sigma concept?”, there is obviously a lot more about six sigma to be discussed. Please free to explore other articles on this blog that deal with six sigma methodology.

For more about quality improvement methods, feel free to explore the following articles:

Six Sigma in Healthcare: Concept, Benefits and Examples

Lean in Healthcare – History, Tools & Examples

Total Quality Management Principles, Concept and Importance

Quality Improvement in Healthcare – Framework & Methodology

FMEA In Six Sigma: RPN, Tools and FMEA Examples

Kaizen Event – Types, Examples, Agenda and Checklist


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