A common misconception is that preventive action is to avert the occurrence of a similar potential problem. This process is all part of corrective action, because it is a process of determining such similarities that should take place in the event of a discrepancy.
Preventive action is any proactive methodology used to determine potential discrepancies before they occur and to ensure that they do not happen (thereby including, for example, preventive maintenance, management review or other common forms of risk aversion). Corrective and Preventive Actions both include investigation, action, review, and further action if so required. It can be seen that both fit into the Plan Do Check Act philosophy as determined by the Deming - Shewhart cycle.