ITIL defines an incident as an unplanned interruption to or quality reduction of an IT service. The service level agreements (SLA) define the agreed-upon service level between the provider and the customer.IT incident management is an area of IT service management (ITSM) wherein the IT team returns a service to normal as quickly as possible after a disruption, in a way that aims to create as little negative impact on the business as possible.
Incidents differ from both problems and requests. An incident interrupts normal service; a problem is a condition identified through a series of multiple incidents with the same symptoms. Problem management resolves the root cause of the problem; incident management restores IT services to normal working levels. A problem is an underlying issue that could lead to an incident. Incident management helps keep an organization prepared for unexpected hardware, software and security failings, and it reduces the duration and severity of disruption from these events.