Root cause analysis is an action that helps to filter out the vital few factors from trivial many that are responsible for the product nonconformance. The basic rule that needs to be followed is that, cause needs to be Actionable. One cannot conclude that Man/ Mother earth is the root cause. The factor that is identified as the root cause needs to be eliminated/controlled from the process as part of continuous process improvement. The different techniques that are useful in root cause analysis are the 5 why's technique, Affinity diagram and The Fish bone analysis. The basic ideology for the root cause analysis is the identification of the source, so that the a proper control strategy can be designed. Sometimes, Various statistical methods like Hypothesis testing, ANOVA may also be used in root cause analysis.