Six Sigma is a creative and flexible series of methodologies aimed at improving organizational process quality and effectiveness. It provides tools for companies to enhance the potential of their business processes. This increase in efficiency and decrease in process variance helps minimize errors and boost profits, employee productivity, and product or service quality. In this article, let us explore the six sigma methodology in detail.
Characteristics of Six Sigma
Statistical Quality Control
Six Sigma is explicitly derived from the Greek alphabet from the Greek letter ? (Sigma), denoting the Standard Deviation in Statistics. Standard Deviation is used to quantify variance and is an essential method in terms of the output's quality to measure non-conformance.
Methodical Approach
In theory, Six Sigma is not merely a quality management technique. It features a well-defined methodical application approach in DMAIC and DMADV that can increase output quality. DMAIC is an acronym for Design-Measure-Analyze-Improve-Control. The alternative method DMADV stands for Design-Measure-Analyze-Design-Verify.
Fact and Data-Based Approach
The scientific basis of the technique is demonstrated by the statistical and systematic aspects of Six Sigma. This accentuates an essential feature of Six Sigma that is focused on facts and data.
Project and Objective-Based Focus
For an organization's project customized to its specifications and demands, the Six Sigma process is applied. In order to get the best results, the procedure is flexible to fit the requirements and circumstances in which a project operates.
In addition, Six Sigma is also objective-based. In the Six Sigma method, the management needs some incentive to invest. It is aimed at enhancing profitability and generating financial capital.
Customer Focus
For the Six Sigma approach, the customer focus is fundamental. The criteria for quality enhancement and control standards are based on the explicit requirements of customers.
Teamwork Approach to Quality Management
The process of Six Sigma allows organizations to coordinate when it's about regulating and enhancing quality. In the Quality Management team, depending on an individual's role, Six Sigma requires a lot of training.
Six Sigma Methodologies
Six Sigma offers two main types of improvement processes. One is DMAIC, and another one is DMADV. So these two processes are appropriate for two different situations.
Define, Measure, Analyse, Improve, and control are the five steps in the DMAIC Process, and this process is used for improving an existing process. If you have a process, and you want to improve that process, i.e., you want to bring the process's performance to the Six Sigma level, and for this case, you will be using the DMAIC process.
If you want to design a new process, and you want to create in such a way that this new process leads to 6 sigma performance, then, in this case, you will use the method called DMADV. So DMADV is used for all new processes, not the existing processes. This methodology is also called DFSS, or Design for Six Sigma. And the five steps in this process are Define, Measure, Analyse, Design, and Verify.
As you can see, the first three steps are common in both these processes, and the difference lies in the bottom two processes.
DMAIC Methodology
There are five stages of the DMAIC project methodology:
- Define: The team defines the problem statement during this process
- Measure: The team maps the current method of the identified problem statement here, collects information, recognizes and understands the root cause of the issue
- Analyze: To reduce the flaws & waste of the current process, the team analyses the data & process
- Improve: When the data & procedure are evaluated, the team uses the improvement suggestions to work on the defects
- Control: In the final step, the team will document how they will pass on the process changes to the workers working within the process
DMADV Methodology
There are five stages of the DMADV project methodology:
- Define: The project objectives and deliverables are defined here
- Measure: Once the goals are identified, the team will measure the critical of its deliverable factors
- Analyze: The teams will evaluate various process options here that will best meet the deliverables needed
- Design: Here, the team documents the detailed process that meets the deliverables
- Verify: Here, the team verifies the targets & results achieved through the newly designed process
How Can Six Sigma Help Companies Improve Quality and Productivity?
Six Sigma is a problem-solving, high-performance approach to examining the causes of process variance and evaluating acceptable solutions, which is increasingly common in today's world. To maximize productivity, Six Sigma's implementation decreases company variability and waste. In the table below, you will find that the defects decrease as the Sigma level increases.
| Sigma Level | Defect Rate | Yield |
| 2? | 308,770 DPMO | 69.10% |
| 3? | 66,811 DPMO | 93.33% |
| 4? | 6,210 DPMO | 99.38% |
| 5? | 233 DPMO | 99.97% |
| 6? | 344 DPMO | 99.99% |
There is a mathematical sense to the word Six Sigma. If you assume that your business process operates like a normal distribution or bell-shaped curve, we can make certain assumptions. So, the process performs within about three standard deviations from the process on average. Suppose we define the quality of the process, using upper and lower specification limits. In that case, a Six Sigma process is one, where the nearest specification limit is at least six standard deviations away from the average. The number of standard deviations from the average and the nearest limit is also called the Sigma level. Sigma levels equate to a yield percentage or success rate.
So, a Six Sigma process only has 3.4 defects for every 1 million times that you run the process. That is nearly perfect. The higher the Sigma level, the less chance of a failure in the process, which reduces waste, inefficiency, and ultimately rework cost, directly impacting a company's financial performance.
Final Thoughts
Organizations using the Six Sigma methodology have minimized waste, increased profit, and increased shareholder value. When many of its workers are educated in the methodology, an organization gains the most from Six Sigma.
To learn more about these methodologies, individuals and enterprise teams need to get trained in popular quality management certification courses like Lean Six Sigma or Six Sigma today! Some of the popular Quality Management Certification Courses that individuals and enterprise teams can take up are:
