Root Cause Analysis

Trees Tools (Cause Analysis/Transitional CA)

The following tools may be most effective for events that have one problem
but potentially many solutions.

5 Why

Figure 4 : 5 Why Quick Facts

This method of RCA is one of the most basic tools available and is commonly
used. First, the problem statement is identified. Then ask Why the problem
occurred, including multiple responses when applicable. Continue to ask Why
for each response until the arriving at actionable root causes. At this point,
eliminate each response based upon facts until only actionable root causes
remain. Note that Why should be asked as often as needed, whether more or
less than five times, until this point is reached. The five why method facilitates
solving the problem at the source, i.e. on the shop floor, and can be used with
very little training on the simplest of problems. It also works well at
creating/changing the culture to one where solving problems is common
place. This tool is NOT for complex/complicated root cause events, because it
only identifies one root cause. It is best utilized on the shop floor for gathering
immediate data.

An example of this tool is shown in the diagram below:

Figure 5 : Example of 5 Why

NOTES:

____

____

____

____

____