Root Cause analysis (RCA) is the formal search for an individual or group of interacting true causes of a problem. The difficult part of professional problem solving is to identify the right tool(s) capable of identifying the true root cause(s) of a problem and not just the symptoms. It is common to find more than just one root cause to a problem, so be skeptical if you just find one root cause to any problem. RCA can be pointed at any simple and complex problem but the designated problem solver has to know what technique to use for different types of problems. For example, let’s look at two different issues in need of solutions:
1. Fast food drive-through window customers complain that their orders take too long to get filled.
2. You cannot produce good quality plastic parts made from your new machine that has 25 knobs on it for the control settings.
You would hopefully apply different techniques to find out the root causes for each of the above problems but often, in business, that is not the case. Too often, the same tool is applied to solve every problem. In the worst case scenario, the ever popular “GOFAAT” Problem Solving Method (Guessing One Factor at A Time) is used to attempt resolution for both problems.
Using the GOFAAT method to solve problem #1 would look like this: The restaurant manager would run around after each customer complaint and scold employee Joe one day, then employee Mary or Larry the next day and then scream at the slow cooking french fry machine the day after that. GOFAAT problem solving is a common but ineffective way to attempt problem solving but this fact does not dampen its popularity. It is certainly not called GOFAAT by any of its fans but it needs to be labeled as such to expose some organizations to their shortcomings in their problem solving efforts.
Using the GOFAAT method to solve problem #2 would look like this: mold machine operator Terry would spin dial number 7 (lucky 7) a little to the right when things go wrong in the hope that this will make the quality problem go away. Mold machine operator Jerry would spin dial number 13 a little to the left when things go wrong, hoping for a miracle. The Clever mold machine Operator Tito would spin dial number 3 and 5 far to the right when things go wrong in hopes of solving the problem. By the way, Terry, Jerry and Tito never talk to each other because they work on different shifts and management does not allow this group the time to discuss their issues. Unfortunately, this is a common situation that many professional problem solvers encounter when they investigate certain serious problems in a business.
There are roughly 18 different families of Root Cause Analysis Techniques used today. They are listed below. The lower numbers generally depict simpler and more unsophisticated techniques and the higher numbers generally require more training and experience to apply those methods correctly. There are 3 groups of problem solving techniques: Groups A, B and C. Group A techniques can be used by a small team of would-be problem solvers with little training. Group B and C techniques require more training and even software to solve the problems.
Group A Problem Solving Techniques include Methods #1-5, which include:
1. GOFAAT method (Guessing One factor At A Time)
2. “Whack-A-Mole” Problem Solving method
3. Total Quality Management (TQM) > other Basic Brainstorming Techniques
4. Failure Mode and Effects Analysis (FMEA) > Disciplined Gap Analysis > Closure
5. Plan-Do-Check-Act (PDCA) continuous improvement techniques
Problem Solving Technique #1 listed above is the previously mentioned GOFAAT method (Guessing One factor At A Time). This method requires no training to apply and can be used by an individual or a small team to attempt resolution of a problem. The use of this tool as the primary way of solving problems would be at the bottom of the scale of sophistication when it relates to competency in problem solving. It would be a matter of luck if the GOFAAT problem solving method actually solved any problem anywhere.
The second most undesirable Problem Solving Technique is what I call the “Whack-A-Mole” method. It is very popular amongst professionals and managers but it is unproductive and it generates a lot of wasteful and useless action. Here is how the Whack-A-Mole method works: A certain manager runs a large factory with 550 people who sew and glue pieces of material together to make purses. The manager of this factory lives a complicated life with several disasters erupting in his/her business every few days; sometimes a few disasters erupt each day. Using the Whack-A-Mole method, this purse factory manager moves his/her best people to fight a problem in one corner in the business where the big problems are creating chaos. Everything else in the factory gets a much lower priority while this “Whacking” goes on. A few days later, the Manager moves these problem fighters to fight another disaster that erupted in another corner of the purse factory. The manager does not have time to worry if the last fire was fully put out, he/she only cares that it was tamed down and off of his/her radar screen of the top 3 issues.
Whack-A-Mole efforts often address the symptoms of a problem and not the true root causes. It is used by frantic, stressed-out, untrained and unenlightened professionals who believe that any intense group of activities will always yield good results. Unfortunately, only logical, efficient and effective actions get results. Professionals need to learn how to work smarter and not harder.
The GOFAAT and Whack-A-Mole methods can lead to chaos and unresolved issues in business.
The rest of the Group A Problem Solving Techniques on the list are more professional types of problem solving techniques that individuals or ad-hoc teams can use after a certain amount of specialty training. The root causes for low complexity problems could be identified with methods #3-5 with the use of friendly debate, team consensus and the democratic process of team voting. Hard statistics and data verification of root causes are usually not used for this group or problem solving techniques. These techniques can be effectively used on simpler problems. They might not always get it right but most of the time their efforts will pay off, if these methods are used correctly in a disciplined way.
Group B Problem Solving Techniques #6-11 include:
6. Lean Manufacturing > Lean Office
7. Time > Motion Studies / Spaghetti Charting
8. Seven Basic Tools of Quality
9. Lean Kaizen Events
10. Process mapping with 10 layers of Analysis
11. Six Sigma and/or Lean > TRIZ
Most of these techniques require very accurate information and/or data to be successful. These tools could be used to address the Not-So-Fast drive-through window customer complaint problem mentioned at the start of this article. A Lean Six Sigma Green Belt, Black Belt, Lean Master or other highly skilled professional has the ability to solve these types of problems by using the right tools at the right time. Specialized training is required to correctly execute these techniques. These Group B problem solving techniques have a higher probability of identifying the correct root causes compared to Group A techniques. Group B techniques should be used for problems that are more difficult to solve. These methods should be applied when simple team brainstorming will not yield the true root causes.
Group C Problem Solving Techniques #12-18 include:
12. 3D > Multi-stratification-level graphing
13. Statistical Hypothesis Testing
14. Simple Regression Analysis
15. Multiple Variable Regression
16. Neural Networks > DOEs
17. Off-The-Chart DOE Optimization
18. Artificial Intelligence
These techniques require a certain amount of accurate data about the problem that will be analyzed with specific software to enable the problem solving technique to be successful. These tools could be utilized to address the bad quality plastic parts story mentioned at the start of this article. The skills required to use these problem solving techniques would be possessed by Lean Six Sigma Black Belts, Master Black Belts and other highly skilled and trained professionals. These techniques are typically applied when all other efforts have failed to get to the root cause and solve the problem.