Things don’t always go according to our plan regardless of how much thought has gone into a project.The unexpected and unforeseen have a way of sneaking in when we’re not looking for them. The term ‘hindsight is a wonderful thing’, whilst cliché, is accurate. So how do we turn the benefits of hindsight to our advantage?

To prevent ongoing problems, bugs or defects in a project or product development the root cause must be established and addressed. A helpful way to do this is to use the “5-whys” technique.

The History of the 5 Whys

This method was devised by Tiachii Ohno, a Japanese industrial engineer at the Toyota Motor Company, and forms the basis of the exceptionally successful Toyota Production System. Ohno encouraged his team to question problems on the manufacturing floor until they found the root cause. It has been further developed as the basis for lean manufacturing and is a very good fit for resolving issues in digital product development.

How it works

As the name suggests, the “5-Whys” works by asking “why” five times or until the root cause becomes apparent. First, the team asks “why” a problem or issue has arisen and records that. If the recorded response does not identify the root cause then it is queried in the same way. This may continue for five rounds of questioning.

As Tiachii Ohno says in his book, Toyota Production System: Beyond Large-Scale Production:

“..by repeating why five times, the nature of the problem as well as its solution becomes clear.”

Tiachii’s famous example revolves around a robot stopping. This may not be as relative to a digital product so I offer this example:

• Why did the user receive an error page when attempting to logging in?
• There was a bug in the login page
• Why was there a bug in the login page?
• There was an update made to the production application instead of the staging version.
• Why was the update made to the wrong version?
• The developer was unaware of the correct procedures for launch.
• Why was the developer was unaware of the correct procedures?
• The induction process is lackingnecessary details.

The 5 Whys Meeting

The procedure of asking “why” five times should happen in a meeting with all members involved in the development. Let’s be honest, not everyone loves meetings and they are often unproductive. So, assign a leader for the meeting – someone who is focused on resolving the issue in a timely manner. Follow these steps for a successful 5-Whys meeting:

1. Invite everyone involved in the product development process. All parties need to be represented to prevent the meeting becoming a blaming session on a department that is not represented.
2. Assign an unbiased leader (as mentioned).
3. Proceed through the process of asking “why” 5 times.
4. Record the answers, identify the root cause and assign responsibilities for achieving the solution.

Two things to consider: 1- Each answer must be factual, something that has happened. Theorising is not helpful. 2- Using this process it is commonplace to uncover a technical fault as a result of human error. It is pivotal to remember that the purpose of this technique is not to assign blame. It is to understand WHY something unexpected happened and set a plan of action to eliminate this re-occurring.

Why use the 5 Whys?

The benefit of holding “5-whys” meetings is in reducing the time required to resolve ongoing problems. A strict, brief agenda and efficient leader will facilitate this.  It is important to note that this technique is recommended for small to moderately difficult problems or issues with process. For larger scale problems a procedure such as Cause & Effect Analysis may be required.