5 Whys

The 5 Whys is an easy and effective tool that allows you to identify the root cause of a problem. It can be used for troubleshooting, quality improvement and problem-solving, being more efficient when used to resolve simple or moderately difficult problems.

Format WorkshopTimeframe 1.5-2 hoursGroup Size 10-15Facilitation Level MediumRequired Materials Excel spreadsheet table


  • Assemble a team. Gather together people who are familiar with the specifics of the problem, and with the process that you are trying to fix. Include someone to act as a facilitator, who can keep the team focused on identifying effective counter-measures.
  • Define the problem. If you can, observe the problem in action. Discuss it with your team and write a brief, clear problem statement that you all agree on. Then, write your statement on a whiteboard or sticky note, leaving enough space around it to add your answers to the repeated question, "Why?"
  • Ask the First "Why?". Ask your team why the problem is occurring. Asking "Why?" sounds simple, but answering it requires serious thought. Search for answers that are grounded in fact: they must be accounts of things that have actually happened, not guesses at what might have happened. This prevents the 5 Whys from becoming just a process of deductive reasoning, which can generate a large number of possible causes and, sometimes, create more confusion as you chase down hypothetical problems. Your team members may come up with one obvious reason “why”, or several plausible ones. Record their answers as succinct phrases, rather than as single words or lengthy statements, and write them below (or beside) your problem statement.
  • Ask "Why?" Four More Times. For each of the answers that you generated in Step 3, ask four further "whys" in succession. Each time, frame the question in response to the answer you have just recorded.
  • Know When to Stop. You will know that you\\'ve revealed the root cause of the problem when asking "why" produces no more useful responses, and you can go no further.
  • Address the Root Cause(s). Now that you have identified at least one root cause, you need to discuss and agree on the counter-measures that will prevent the problem from recurring.
  • Monitor Your Measures. Keep a close watch on how effectively your counter-measures eliminate or minimize the initial problem. You may need to amend them, or replace them entirely. If this happens, it\\'s a good idea to repeat the 5 Whys process to ensure that you\\'ve identified the correct root cause.


  • Analysis technique that is simple to use.
  • Helps determine the cause of a problem.
  • Identify the root of the problem.


  • The "5" in 5 Whys is really just a "rule of thumb". In some cases, you may need to ask "Why?" a few more times before you get to the root of the problem. In other cases, you may reach this point before you ask your fifth "Why?" If you do, make sure that you haven't stopped too soon, and that you're not simply accepting "knee-jerk" responses.
  • The important point is to stop asking "Why?" when you stop producing useful responses.
  • As you work through your chain of questions, you may find that someone has failed to take a necessary action. The great thing about 5 Whys is that it prompts you to go further than just assigning blame, and to ask why that happened. This often points to organizational issues or areas where processes need to be improved.
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