Root cause analysis is an essential technique to be employed by any thorough and well thought out project mismanagement team and or project management team leader as it helps address, often times, issues that may exists in the background that may differ slightly from the obvious ones at the surface. Specifically speaking, the technique of root cause analysis refers to the act of analyzing a series of variances, risks, or defect that may exist in and around the project or any specific or particular component of that project and attempt to determine through careful review the actual root causes, or unique underlying factors, that may exist which is ultimately leading to this unfavorable result, and which would need to be addressed and or compensated for if there is the goal to alter the outcome.One single root cause can actually have a significant impact, and can in fact be the cause of a number of defects or risks.
This term is defined in the 3rd and the 4th edition of the PMBOK.