RCA Methods

Fishbone Diagram

5 Why's

RCA Method

5 Why's

5 Whys is the original technique developed by Sakichi Toyoda for root cause analysis at Toyota factories. It is addressing everything with a ‘why’, just like a curious child. Keep asking ‘why’ until you’ve reached the root cause. You can continue this process until you reach a stage where there is no need to ask ‘why’ again. At that point, you should have reached the root cause of the problem.

• 5 Whys is a simple and intuitive method for identifying the root cause of straightforward issues. It involves asking “why” until the root cause is identified.
• 5 Whys method is easy to understand and implement however this may not be suited for complex issues.

Pros and Cons: 5 Whys is easy to use and is a straightforward approach but it may not be sufficient for complex issues as it relies on intuition and experience.

RCA METHOD

Fishbone Diagram

The Ishikawa method or commonly known as the Fishbone Analysis emerged from quality control techniques employed in the Japanese shipbuilding industry by Kaoru Ishikawa. The shape of the resulting diagram looks like a fishbone, which is why it is called a fishbone diagram. This diagram is built on the idea that multiple factors can lead to a failure/event/effect.

The Ishikawa Diagram is a structure way of exploring the potential cause of a problem. It categorizes causes into a variety of factors like people, equipment, process, etc. This helps us understand the relationships between causes and is better presented with a visual representation however this relies mostly on a subjective interpretation of the causes.