Making Improvements with Six Sigma Root Cause Analysis
When things aren’t going the way they should, it can often be quite difficult to identify what is actually causing the problem. Despite the fact that it can take a lot of work, root cause analysis is extremely important because of the fact that it will allow you to not just cover up issues, but actually address them directly.
In many cases, this will allow you to make significant long term improvements to your facility. With that in mind, all facilities should have a method of digging into problems to discover the root cause. For a growing number of facilities, this methodology comes right from their existing Six Sigma strategies.
What is the Six Sigma Root Cause Analysis Strategy?
The Six Sigma root cause analysis strategy is often known simply as the “Five Whys.” As you might expect, it gets this name because of the fact that it encourages those working on problems to ask “why?” until they get to the root cause of the problem.
In reality, you may have to ask yourself (or your team) why only once or twice or far more than five times. The important thing is to make sure you are asking the right questions and that you don’t stop until you get to the actual root cause of the problem.
Kaizen Guide: Better your business with continuous improvement
To be successful, you can’t make an improvement once and forget about it. Effective lean businesses use kaizen, which means “continuous improvement”. In kaizen, everyone looks for ways to improve processes on a daily basis. This Kaizen Guide explains the kaizen mindset, basic kaizen concepts including the PDCA cycle, and real-world examples.
Before you ask yourself ‘why’ at all, however, you need to clearly define the problem. The Six Sigma standard suggests that you write it out so that you and the entire team have a single point of focus when working on the issues. This will help you to avoid getting distracted when performing this root cause analysis.
To get a concrete idea of how this could work in a normal, everyday situation, follow this simple example. If you are driving home and your check engine light came on, you might run through a Six Sigma root cause analysis to figure it out. First, you define the problem statement, which might be, “Your vehicle is operating, but the check engine light has come on.” You would then begin asking why? For example:
- Q) Why did the check engine light come on?
o A) Because the serpentine belt came off. *You can confirm this by looking under the hood or seeing if other systems that rely on this belt are impacted.
If you determine that this is not the root cause of your problem, you will move on to the next why:
- Q)What is another reason why the check engine light came on?
o Because I have not changed the oil in eight months. *Again, confirm this by checking the oil levels or taking it to a mechanic.
If you find that this is the cause, you will still need to continue asking why, since the oil not being changed is not the root cause:
- Q) Why wasn’t the oil changed on time?
o Because I forgot to schedule the oil change.
- Why did I forget to schedule the oil change?
o Because I stopped using my calendar app on my phone
You now know that the root cause to your engine light is actually the poor organizational skills and a failure to use the proper tools to help prevent these types of things. As you can see, by getting to the root cause of this issue, you actually likely avoided a variety of other problems in the future (related to the root cause of poor scheduling and organization).
Of course, you will have to take steps to fix the problem, but once you have identified the root cause, that won’t be difficult at all.
Keeps the Focus
One of the biggest benefits of the Six Sigma root cause analysis system is that it helps to ensure that everyone working on a problem stays very focused. It can be tempting for many people to get off topic and start looking into potential issues that aren’t related to the actual problem at hand.
While this can be beneficial for discovering other issues, a root cause analysis session is not the right time for it. By continuing to ask ‘why’ based questions, it allows you to keep moving forward in the investigation.
Easier to Identify the Actual Root Cause
Another major advantage to this system is that it is much easier to know when you have reached the actual root cause. When you can’t think of any more ‘why’ questions that make sense to ask, that almost certainly means that you’ve reached the root cause.
Some people may be tempted to keep finding and asking these questions (as you can always ask why) but when it is clear that all the questions being asked aren’t actually helping to drive toward a root cause, the process is over. You can then find where the questions ended, and that is the root cause.
Finding the Solution
With the Six Sigma root cause analysis strategy you are not only able to find the actual root cause much more effectively, but the solution to the problem is often built right in. Once you see where the root cause is, you can often go back and look at the answers to the previous questions to come up with ideas on how to address that root cause.
In a way, the whole process of finding the actual cause of issues is actually going to be preparing you for the problem resolution as well. This will allow the problem analysis and investigation to go much more quickly, while also being more effective.
For example, if there is a safety issue where there are frequently accidents or near misses in an area where there are frequently people walking as well as high-low’s driving, you can use this method to ask several why questions, to which the answer may lead to the fact that there is no easily identifiable difference between where people should be walking and where vehicles should be driving.
Once you get to this conclusion, you can quickly realize that adding floor marking tape (which can be found here) that clearly distinguishes where vehicles need to drive will solve the problem. You can also determine whether or not it is necessary to use color coding for this, or even using floor marking shapes (like these) for further benefits.
The bottom line with the Six Sigma root cause analysis strategy is that it will help you to more quickly determine what exactly is causing the problem, while at the same time coming up with a solution. It is well structured and can be effective for nearly any type of problem imaginable.
- Seven forms of Waste – Lean Six Sigma
- 2014 the Year of Data Innovation for Lean
- Eight Steps To Practical Problem Solving
- Change is Necessary
- Why You Should Use Takt Time Production & How To Do It
- How Kaizen is Imperative to LEAN Success
- Six Sigma Principles– creativesafetysupply.com
- Accident Investigation – Root Cause Analysis– creativesafetypublishing.com
- Why Ask Why?– lean-news.com
- Using Lean Six Sigma to Solve Workplace Production Issues & Inefficiencies– blog.creativesafetysupply.com
- 8 Requirements for Six Sigma Success– 5snews.com
- Design For Six Sigma (DFSS)– iecieeechallenge.org