Problem management aims to resolve the root causes of incidents and thus to minimise the adverse impact of incidents caused by errors within the IT infrastructure, and to prevent recurrence of incidents related to these errors. A "problem" in this context is the unknown underlying cause of one or more incidents, and a 'known error' is a problem that is successfully diagnosed and for which either a work-around or a permanent resolution has been identified. The CCTA (Central Computer and Telecommunications Agency) defines problems and known errors as follows: