The DMAIC is one of Six Sigma's most effective problem-solving methodologies. It is divided into five stages: Define, Measure, Analyze, Improve, and Control. This article will discuss the Analyze phase, which is the third phase of DMAIC. Specifically, we'll discuss what this phase entails and the tools that teams can use to identify potential causes and conduct root cause analysis (RCA).
What is the Analyze Phase?
The analysis phase, as the name suggests, entails determining the root cause of the problem. This allows the Six Sigma project team to go deeper into the problem and permanently solve it. For example, in a manufacturing process, this might imply looking into what causes product defects. This is also known as variation, and it is something that the customer does not want.
Tools for Identifying Possible Causes
The Analyze phase entails identifying all potential causes. Because this is Six Sigma, teams are in for a treat. There are tools available to help them eliminate the guesswork associated with identifying potential causes.
Here are the most widely-used tools for doing this:
- Process map – This is a flowchart that shows the process in its current state. This means all the steps, actions, inputs, outputs, and other details are illustrated for a better understanding of the process as is. This allows the team to visualize potential causes by looking at the changes in the process.
- Fishbone diagram – Also known as a cause-and-effect diagram or Ishikawa diagram, a fishbone diagram allows the team to group potential causes into related categories. The problem being experienced is written as the head of the fish. Each bone on the spine represents a category. Then lines are added to each bone, and these are the potential causes.
Tools for Root Cause Analysis
After identifying the potential causes, the team needs to perform a root cause analysis (RCA). The main idea behind RCA is to eliminate the problem at the root so that it does recur. This is important because it means that resources aren’t wasted on dealing with a superficial or wrong cause.
Here are some popular RCA tools:
- Chi-square test: This is a test performed to determine whether there is statistical significance between the expected and observed outcomes. If the difference is statistically significant, it means an independent cause is responsible. Otherwise, it could be because of chance and not worth further investigation.
- Regression analysis: Regression analysis is a series of statistical techniques that help identify variables that lead to a particular result. In this case, it can help tie which potential causes have an impact on the problem being observed. The team can then know which ones to ignore and which ones pay close attention to, as well as how they are related.
After analyzing the problem, improving it is the next step. This is why the Analyze phase is important, as it helps the Six Sigma team identify the exact cause of the problem at the root. This allows the team to eliminate it once and for all to reduce the incidence of defects.
Original Source: Analyze Phase of a Six Sigma DMAIC Project