A while ago, I read an excellent book called The Lean Startup by Eric Ries. The Lean Startup describes a new approach for startups, using concepts like building a minimum viable product (or MVP) as soon as possible, innovation accounting, pivots and more. It’s based on lean manufacturing, a production process pioneered by companies such as Toyota and Ford. A highly interesting read if you are interested in starting your own business.
The book also details the use of 5 Whys, a technique to explore cause and effect relationships when particular problems are faced. Its primary goal is to find the root cause of an issue, by repeating the question “Why?” five times. Each answer forms the basis for the next question. It takes about 5 iterations on average to get to the root cause of the problem.
Here’s an (fictitious) example. Suppose a machine stopped functioning:
- Why did the machine stop? There was an overload and the fuse blew.
- Why was there an overload? The bearing was not sufficiently lubricated.
- Why was it not lubricated sufficiently? The lubrication pump was not pumping sufficiently.
- Why was it not pumping sufficiently? The shaft of the pump was worn and rattling.
- Why was the shaft worn out? There was no strainer attached and metal scrap got in.
The root cause was that there was no strainer attached. If you didn’t ask the 5 whys, you might not ever fix that problem, but instead just try to patch up the resulting issues it caused. The idea is that you make proportional investments to fix each of the 5 whys. This way, the total investment in time fixing the issue won’t be too big but you should still see valuable improvements afterwards.