The "5 Whys"​ Method (5Ys) - how to collaboratively identify and solve the root cause of problems

Updated: Nov 15, 2019

The problem you are facing might not be the real problem you are facing.

There might be another problem making the current problem occur. A cause to the problematic effect which is the real problem.

Without addressing the cause the problem will simply reoccur.

The founder of the company which is now Toyota knew this. Sakichi Toyoda (1867 – 1930) was an inventor and an influential figure in the Japanese industrial revolution. He is accredited to creating the 'Five Whys Method' - a simple but powerful tool for getting to the route of a problem. Its become known as "The Five Whys" (or simply 5Ys) and is part of the Toyota Production System.

Sakichi Toyoda - Source: Wikipedia

What is the "5 Whys" Method?

Like all of the best tools, "5 Whys" is easy and simple. When you come across a problem you ask "Why" it has occurred. After each answer, you ask "why" again. Five times. At each stage, you can consider putting "countermeasures" in place which can help to ensure that the stage of the problem does not occur - basically preventing the initial problem from happening.


Here is a crude example of how it works:

  • Initial Problem Statement: "The electricity in our factory keeps tripping causing a 30 min downtime in productivity".

  • Why 1: "Staff are spilling drinks that they are carrying over an electrical power supply".

  • Why 2: "Because they keep colliding with each other whilst travelling from the canteen to his workstation".

  • Why 3: "Because they are thirsty and want to drink at their workstations".

  • Why 4: "Because company policy is such that the time allocated for breaks does not allow staff time to finish their drinks within the time of the break".

  • Why 5: "Because HR worry that to allow longer breaks will mean we will be less productive".

You could keep going if you think there is more value in asking Why more times - or if you think you find the root problem earlier you can stop at that.

Taking the above example a team c