A Quality Circle leader is confused about the seven basic quality tools, and approaches you to help him in using a tool for identifying the root cause of the problem. Discuss with example what tool will you advise him to use and how it is used.

Question : which quality tool is used to identify the root cause and needs to be advised to the quality circle leader? with examples.
Question : are all quality tools used to identify the root cause? if not , please let me know which ones do.