The Quality Toolbox: Problem Solving Tools

5 Whys: This technique can be used very effectively during cause & effect analysis to drive to true root cause. Anyone with small children has first-hand experience with this problem-solving tool, although in the business environment root cause should not end at “Because I said so!” Although the word “Why?” may be your three-year-old’s favorite word, it could also teach you a valuable problem-solving technique. By repeatedly asking the question “Why?” (five is a good rule of thumb), you can peel away the layers of symptoms which can lead to the true root cause of a problem.

The biggest mistake that most organizations make in problem solving is to try to fix a symptom instead of the root cause. Only addressing a symptom will result in the root cause manifesting in the form of another symptom, and the problem will continue. Although this technique is called the “5 Whys,” it may be necessary to ask the question fewer or more times than five to drive to root cause in some instances.
An example of using the 5 Whys is presented in the attached Figure. Now if we really wanted to solve this problem permanently, we could implement an oil level sensor Poka-yoke that would alert the operator and/or shut down the machine before a critical level was reached. Hopefully it is becoming clear how these tools can all work together to provide a solution!