The DMAIC process streamlines and organizes this process into phases: Define, Measure, Analyze, Improve, and Control.
The “A” in DMAIC stands for Analyze. The “Analyze” phase involves the Root Cause Analysis (RCA) of any problem, issue, or situation. Important note: The root cause is not the problem itself. The root cause creates the problem. When searching for the root cause, asking “Why” is an important step. In fact, there is a specific tool for this – a Why-Why Diagram. Why-Why Diagrams look like a tree. The tree has roots – see the connection?
As an example (and this is a true story), quite a few cars stopped running after drivers purchased fuel at several Sam’s and Costco’s. The fuel was traced back to a gasoline tank that mistakenly contained diesel fuel instead of gas. But this wasn’t the root cause. Upon further investigation and digging deeper, the supplier put diesel fuel into the wrong tanker before delivering to Sam’s and Costco. The root cause was either insufficient training or a poor system of checks and balances – or perhaps a combination of both. If we start asking the “why” questions, we can usually arrive at the root cause.
This short video shows you how RCA uses Why-Why in the DMAIC process (Links to an external site.).
Six Sigma teams often have brainstorming sessions to toss around ideas when starting an RCA. For this discussion, you are the Champion of a Six Sigma Team, so you will initiate a Root Cause Analysis.
- Select one of the problems or situations listed below. As noted, you may use a “real” problem if you prefer.
- Meet with a friend, family member, or coworker and conduct a brainstorming session to determine possible root causes.
- List five possible root causes or reasons why this problem or situation exists.
- Rank these five possible root causes in order of importance or probability.
- State one way you might correct the first reason why the problem exists.
- Justify your decision by describing the benefit(s) of dealing with or correcting this first or main root cause.
PROBLEMS: Select one situation or problem from the following list. As an option, you may use a “real life” problem that you are experiencing.
- Why a computer hard drive might malfunction
- Why a customer may not like ordering on a virtual website
- Why an ECPI student may fail an online class
- Why a customer may be displeased with his or her mobile phone plan
- Why a patient may change doctors
- Why a customer may not use online banking
- Why a customer may be unhappy with calling technical support
- Why a car won’t start
- Why it takes too long for food to be served in a restaurant
- Why patients must wait too long to see a doctor
- Why the crime rate is high in an area neighborhood
- Why a printer might malfunction