What Is Six Sigma?
Six Sigma is a systematic approach for eliminating errors. Six Sigma uses statistical methods to improve quality by minimizing variability in business processes, from manufacturing to engineering and purchasing. Six Sigma accomplishes its goal by using two Six Sigma Methods: DMAIC and DMADV.
Six Sigma DMAIC
The Six Sigma DMAIC approach is typically used to improve an existing process. DMAIC is an acronym that stands for:
- Define the problem and desired outcome
- Measure the ability of the process
- Analyze the data and identify the root cause of variations (defects)
- Improve or modify the process so that fewer variations (defects) are produced
- Control the process. Prevent and correct variations before they result in defects
Six Sigma DMADV
When designing a new process, the Six Sigma DMADV is used. It is also known as DFSS (Design for Six Sigma). The DMADV acronym stands for:
- Define design standards that align with the product or process goals
- Measure and identify characteristics of the product or process that are critical to quality
- Analyze the data, and identify possible sources of defects
- Design changes that will eliminate the source of defects or errors
- Verify that the design will meet the requirements
Five Key Six Sigma Principles
Six Sigma success is based on five key principles:
- Focusing on customer requirements
- Using extensive measurement and statistical analysis to understand how work gets done and to identify the root cause of problems (variations)
- Being proactive in eliminating variation and continually improving the process
- Involving people in Six Sigma cross-functional teams
- Being thorough and being flexible
Key Six Sigma Principles – Customer Focus
Six Sigma is about improving quality. The first step in that process is defining what “quality” means, from the perspective of the people whose opinions matter most: the customers. A business needs to measure quality the same way its customers do. By focusing on the customer, a business can improve its products’ quality.
Key Six Sigma Principles – Identify Root Causes
To correctly identify a root cause, a complete understanding of the process is necessary. This does not mean just understanding how a process was designed to work. It means understanding how the process is actually working. To accomplish this you need to:
- Have clearly defined goals for data collection
- Identify the data that needs to be collected
- Have a defined reason for the data being collected
- Establish what insights are expected from the data
- Ensure accurate communication by clearly defining terms
- Ensure that measurements are accurate and repeatable
- Establish a standardized data collection system/process
Once the data is collected, determine whether it is providing the required insight and is meeting the goals that were established. If not, refine the data collection plan and collect additional information.
Six Sigma data collection involves interviewing people, making observations, and asking questions until the answers are found. Ask the questions such as:
- “Why do we do things this way?”
- “What would make your job easier?”
- “What things do you do that seem to be a waste of time?”
Once the data is collected, use it to look for ways to improve or optimize the process by identifying the root cause of variation.
Key Six Sigma Principles – Eliminate Variation
After identifying root causes, make changes to the process that will eliminate variation, and thus eliminate defects from the process. Also look for ways to eliminate steps that do not add value for the customer. This will eliminate waste.
Be proactive in identifying variation and eliminating it. Don't wait for signs of variation to become obvious. Collect data, talk with people, and study the data to find variations in the process that may have become accepted because “that's the way we've always done things.”
Key Six Sigma Principles – Teamwork
Six Sigma involves teams and leaders who take responsibility for the Six Sigma processes. The people on the teams need to be trained in Six Sigma's methods, including the Six Sigma measurement methods and improvement tools that will be used. In addition, they need communication skills so that they can involve, serve, and communicate clearly with both coworkers and customers.
Putting together teams that have members with a variety of skills and backgrounds related to a process will help the team spot variations. For a manufacturing process for example, people from operations, maintenance, engineering, and purchasing should be included.
Key Six Sigma Principles – Be Flexible and Thorough
Six Sigma requires flexibility in many ways. The business’s management system needs to accept positive changes as well as empower change. Employees should be motivated to adapt to change. In the beginning, the benefits of the changes should be made clear to workers. This will help to create an environment where change is more readily accepted.
Key to Six Sigma is the ability to change or adapt procedures as needed. In short, the process required for change should not be so complex that workers and management would rather work with a broken process than fix it.
Six Sigma also requires problem-solving to be thorough. Making sure to understand every aspect of a process—the steps, people, and departments involved—will help to ensure that any new or updated process works.
Six Sigma Quality Management Tools
A variety of tools can be used to support Six Sigma, including Value Stream Mapping (VSM), Capability Analysis, 5 Whys, Plan-Do-Check-Act (PDCA), and Statistical Process Control (SPC).
VSMs are visual maps or flowcharts that enable businesses to understand every aspect of a process and define potential problems. Unlike standard flow charts, VSMs include the internal (departments and workers) and external (customers and shipping) factors that affect a process. By completely mapping out a process, it is much easier to define potential problems.
Capability Analyses measure the ability of a process to meet a business’s needs. This tool allows businesses to quantify the relationship between the customers’ needs and the current process’s ability to meet those needs, allowing businesses to make processes that are customer-focused.
Five Whys enable businesses to hone in on a problem’s root cause and fix it, rather than addressing surface-level issues that temporarily improve a situation. Doing what its name suggests, Five Whys requires workers to ask “why” until the root cause of a problem is identified.
PDCA is a lean tool that solves problems using four steps: Plan, Do, Check, Act. Once a root cause is identified, this tool allows it to be addressed systematically by creating a solution, testing it, reviewing its success, and finally implementing it.
SPC is a quality control tool that monitors and controls a process by tracking its metrics. A common way to implement SPC is to use a control chart, which records information and allows businesses to see when a process stops working. Once an issue is discovered, the process can be altered to solve any new problems that occur.
Key Six Sigma Principles – Clear, Effective Visual Communications
Six Sigma involves change, and change requires effective on-going communication. Old habits need to be broken and new habits established. Graphic Products offers an array of supplies that can help make Six Sigma successful in your business including printers and labels.
Other lean methodologies can also be used to support Six Sigma. Lean tools like Kaizen can be used to help create an environment where changes are accepted and business practices are continuously improved upon, while 5S can be used to make problems easier to spot as well as create standardized processes.