The following is taken from “Stop problem solving” by Gareth Kay.
“As part of its effort to reinvigorate itself, Toyota introduced the approach of kaizen (simply meaning ‘change for better’). Overall, this was about ensuring continuous improvement but one of its key tenets was the Five Whys technique. Taiichi Ohno [pictured], the architect of the Toyota Production System in the 1950s, encouraged his team to “observe the production floor without preconception. Ask ‘why’ five times about every matter … by repeating why five times, the nature of the problem as well as its solution becomes clear.” He goes on to offer the example of a robot stopping. By asking why five times, the problem to be solved becomes clearer: no filter on the oil pump, rather than an overloaded circuit to which initial analysis would point. The ability to ask why until you can ask why no more is an incredibly important skill we forget far too often. When we do this, we begin to find the real, root problem we need to solve, rather than the symptom that is far too frequently the result of the typical problem-solving approach.”