Cause & Effect (C&E) Diagram

Also know as a Fishbone or Ishikawa, it is a collaborative tool used by a team to help identify all possible causes for a particular undesirable effect (e.g., a defect). It digs into potential root causes by exploring effects from different perspectives, such as the 6Ms.
Related StatStuff Video: 
   -Section 5-Measure Phase, Lesson #23 - Identify Root Causes – C&E Diagram