How and when to use the 5 Why technique
The “5 Whys” method is a simple problem-solving technique that helps those who use it to quickly get to the root cause of the problem. In everyday production or support processes, problems frequently arise and if treated only superficially, tend to recur, so the “5 Why” methodology is one of the most effective and accessible methods for identifying the root cause, without requiring complex tools or advanced statistical analysis.
Publicized in the 1970s by the Toyota Production System, the “5 Why” strategy involves approaching any problem by asking “Why?” and “What is the cause of this problem?” in order to go beyond the symptom and get to the real cause of a problem. The number of “5” is not strict, sometimes 3-4 questions are enough, other times 6 or 7 may be necessary, the important thing is the logical deepening process, not the fixed number of 5 steps.
Steps in preparing and implementing 5 Why:
- understanding the problem (maybe by stratifying it), the facts, the problem components
- creating a team of people who know the subject and possibly a “fresh eyes”
- give a maximum of answers for each “Why” question, going progressively deeper. Always check the logical correctness by following the phenomenon, the validity of the answer by “That is why…”
- support the answers with data, reports, measurements, observations
- close the last “Why” with effective corrective measures and use the Action Plan for follow-up
- avoid jumping to conclusions without going through the stages, answers based only on assumptions, stopping too early without getting to the real cause, lack of evidence for answers and totally unapproachable solutions.
The value of the methodology is the disciplined way of thinking it imposes, moving from the symptom to the real cause, and in organizations oriented towards continuous improvement, this remains a basic standard for analyzing problems and preventing them in the long term.
