What is root cause analysis?(RCA)

Testing is activity to find defect, prevent defect and gain the confidence of the software but when we detect the defect, failures we need to find out real reason why that happened? what‘s the root cause of that failure? for that we need to analysis the root cause. When we say the root cause that mean when you fix it, when it get resolved and prevent the recurrence of the problem.


Root cause Analysis is the a systematic way to know actual root cause of our problem. There are server ways to analysis the root cause and different techniques too .Every organizations has different techniques and different method to do root cause activity.Understanding the root cause of defect is an important aspect.Many time (RCA) done once event has occurred. But we may make it useful as pro-active method.

Example of Dish washer:
“Machine is 1 week old (Serial no: 123456) After few minutes of loading utensils I see the foam outside the dishwasher”
Now what will be next? The technician check the dish washer operation to test procedure.Technicians determines the cause or investigate why that happened.
Some of the obvious causes technician discover might be:

Liquid dishwashing soap used instead of automatic dishwasher detergent.

Too much automatic dishwasher detergent.

Examine the drain hose to make sure it isn’t kinked.

There are several tool used for the root cause analysis:

Brainstorming:
It's a process where people get together to examine the problem, where the group quickly generate many ideas for the particular problem.
It's a very useful technique because it uses collective brainpower to generate many ideas in a short period of time.

Fishbone diagram:
It is also known as cause –effect diagram, it's a technique to graphically identify and organize many possible causes of a problem
It's help to identify the most likely root cause of the problem.This tool can help focus problem solving and reduce subjective decision making

As tester , we want not to just detect the defect and report it but we need to think about any potential causes of failures.