# Transitional Root Cause Analysis

## Discussing Root Cause Analysis (RCA) can be made easier using Shon Isenhour's tree diagram.

September 14, 2017

When I discuss RCA I use a method called Transitional Root Cause Analysis or TRCA for short.

It is made up of 10 tools that can be explained and understood in a very short period of time.

In the next few minutes I will demonstrate both the simplicity and rules for use for 3 of the 10 and explain why we consider them transitional in nature.

In this blog we will use what I categorize as the tree methods. These are three tools that build out into a tree root like structure. So let’s take a look: the first one is called the "5 why"  method. It is very common in industry today and is a very basic root cause tool. It is created simply by asking the question why multiple times to create one causal chain. It creates a simple main tap root to build off of.

Now, if we take the 5 why diagram and branch it out by adding more elements at each level then we get a better representation of all of the causes that come together to create an effect. This transition of the 5 why is known as a fault tree. This method allows us to easily see all factors that led to a failure, but sometimes we need to show a bit more information to make the graphic more meaningful.

If for instance, an effect can only occur when all of its causes exist at the same place and in the same moment in time then we use the word "and" at that junction of the roots. If we eliminate either one of the cause then we can eliminate the effect. On the flip side, if either of the causes could precipitate the effect then the word "or" would be placed at the junction. This would be read as this or that could cause the effect above. This allows you to see that both possibilities must be addressed to prevent the cause.

These three tree methods transition from one to the next by adding one simple new feature as needed during the root cause process. First, we take a "5 why" and branch it to get the fault tree then we add in the "and and" or "or" to get logic tree. Three powerful tools that build on each other to get you to the lowest cost solution that mitigates the risk.The other Transitional tools work very much in the same way and allow us to use the right tool for the job instead of trying to use a screwdriver as a hammer.

If you would like to learn more about the Transitional method to RCA please send me an email and I will help you along.

Shon Isenhour, content marketing, Eruditio LLC. This article originally appeared on Eruditio’s website. Eruditio is a CFE Media content partner.

Original content can be found at blog.eruditiollc.com.