I am new to ITIL and Incident classifcations and I am trying learn more about them and understand how they could integrate in our organization. I have found it difficult to find a clear definition of Fault vs. Service Request vs. Technical incidents. I am basing my definitions on this article: http://www.itsmsolutions.com/newsletters/DITYvol6iss27.htm As I understand it: Service Request - Service provided by IT as part of regular administration of a system. Fault - An unexpected error in a system. Technical Incident - An interruption or potential interruption in IT service due to an expected incident caused by some IT policy.