What is fish bone analysis?

It is used for root cause analysis in dealing with quality planning and analysis, 

i agreed with the answer of Mr Alex Al Yazouri.

Also called 'ishikawa diagram'.

It is a tool of root cause analysis.

Very simple but very effective.

By the end of root cause analysis, it takes the shape of fish bone. That is why is called 'fish bone' diagram.

There are other tools also, such as5Ys.

A fishbone diagram, also called a cause and effect diagram or Ishikawa diagram. 

Is a visualization tool for categorizing the potential causes of a problem in order to identify its root causes.