{"id":7856,"date":"2020-03-15T10:49:00","date_gmt":"2020-03-15T14:49:00","guid":{"rendered":"https:\/\/www.shortform.com\/blog\/?p=7856"},"modified":"2022-04-14T17:41:55","modified_gmt":"2022-04-14T21:41:55","slug":"5-whys-analysis-root-cause-analysis","status":"publish","type":"post","link":"https:\/\/www.shortform.com\/blog\/5-whys-analysis-root-cause-analysis\/","title":{"rendered":"5 Whys: How to Do Root Cause Analysis Right"},"content":{"rendered":"\n

When you face a problem, how do you figure out what the root cause was? How do you learn what the right problem to tackle is? <\/p>\n\n\n\n

The solution is the Five Whys: keep asking Why until you find the problem. But how do you do it correctly, and what pitfalls are there in the 5 Whys Analysis? Learn from this Lean Startup guide.<\/p>\n\n\n\n\n\n\n\n

Introduction to the Five Whys Premise<\/h3>\n\n\n\n

A lean startup faces natural tension between opposites: fast and scrappy vs slow and methodical, hacky and agile vs robust and overdesigned.<\/p>\n\n\n\n

Initially, building a product quickly and poorly gets you data faster. But you incur technical debt that will slow development in the future.<\/p>\n\n\n\n

How do you decide where on the spectrum to lie? You need a natural feedback loop to tell you when you\u2019re moving too slowly or too quickly by identifying the root cause of problems.<\/strong> When you face a new problem, root cause analysis tells you precisely why the problem happened, and suggests how to fix it. This prevents overdesign and prevents the problem from happening again.<\/p>\n\n\n\n

The Five Whys Analysis<\/h2>\n\n\n\n

Find the root cause with the Five Whys<\/strong> method. When you see a problem, ask yourself five Whys in succession.<\/p>\n\n\n\n

Here\u2019s an example from Toyota where a machine broke down:<\/p>\n\n\n\n

  1. Why did the machine stop? There was a power overload and the fuse blew.
    1. [If we stopped here, we would just replace the fuse. The fuse would blow again, and we\u2019d replace it again, and so on. We would treat the symptom, but not the cause.]<\/li><\/ol><\/li>
    2. Why? The bearing was not lubricated.<\/li>
    3. Why? The lubrication pump wasn\u2019t pumping.<\/li>
    4. Why? The shaft of the pump was worn.<\/li>
    5. Why? The mechanic forgot to put a filter on, and metal scrap got in.<\/li><\/ol>\n\n\n\n

      The final root cause from asking Five Whys is dramatically different from what you started out with.<\/strong> Because it\u2019s a root cause, addressing it will solve all the problems up the line. If you had stopped asking why at each stage, you\u2019d have addressed only a symptom that will recur, instead of treating the underlying disease.<\/p>\n\n\n\n

      In fact, if you kept asking why a few more times, you\u2019d probably find other root causes to tackle. The mechanic may have gotten insufficient training on this equipment. Repair of this machine might not have a checklist, which is standard practice. Or the mechanic might have just been a bad hire \u2013 in which case bad hiring practices are to blame.<\/p>\n\n\n\n

      This example of Five Whys can be applied to any recurring problem in your startup, whether it\u2019s a problem in customer service, engineering, accounting, or more.<\/p>\n\n\n\n

      The Output of Five Whys: Make a Proportional Investment<\/h3>\n\n\n\n

      Asking Five Whys lets you figure out the root cause. Depending on how grave the problem is, you can then make a proportional investment to fix it.<\/strong><\/p>\n\n\n\n

      This requires you to quantify the size of the problem. You can do this in units of resources \u2013 namely, man-hours or dollars.<\/p>\n\n\n\n

      A problem that occurs once and costs one man-hour to fix doesn\u2019t need a heavy process to fix it.<\/p>\n\n\n\n

      A problem that occurs weekly and requires ten man-hours to fix will suck up 500 hours in a year \u2013 if you can spend 100 hours to solve it completely, it\u2019s well worth it.<\/p>\n\n\n\n

      This calculus doesn\u2019t have to be exact \u2013 often a rough estimate<\/strong> will tell you clearly if fixing the problem is clearly a huge gain, clearly a waste of time, or somewhere on the fence.<\/p>\n\n\n\n

      And you can solve problems iteratively too.<\/strong> For first-time problems discovered with Five Whys, make a smaller incremental improvement to the root cause. If the problem recurs, then you have more information about whether you want to invest more.<\/p>\n\n\n\n

      The Five Whys and proportional investments are a self-regulating process because they slow you down appropriately when major problems happen. The more problems you have, and the more severe they are, the more you invest in solutions to fix them. As better processes reduce the problems, you can speed up again. This adaptive approach helps avoid both over- and under-investment.<\/p>\n\n\n\n

      Avoiding the Five Blames<\/h2>\n\n\n\n

      As powerful as the Five Whys is, it can be difficult to be objective. Sometimes a problem has multiple root causes, leading to finger pointing.<\/p>\n\n\n\n

      Here are a few ways to avoid the Five Blames:<\/p>\n\n\n\n