Some commonly used ITIL terms in service delivery and service support areas are explained below

Incident.

Any event that is not part of the standard operation of a service and causes, or may cause, an interruption to, or a reduction in, the quality of service.

Problem.

The undiagnosed root cause of one or more incidents.

Known error.

An incident or problem for which the root cause is known and a temporary workaround or a permanent alternative has been identified. If a business case exists, an RFC will be raised, but—in any event—it remains a known error unless it is permanently fixed by a change.

Major incident.

An incident with a high impact, or potentially high impact, which requires a response that is above and beyond that given to normal incidents. Typically, these incidents require cross-company coordination, management escalation, the mobilization of additional resources, and increased communications.

Service desk.

A function that provides the vital day-to-day contact point between customers, users, IT services, and third-party organizations. The service desk not only coordinates the incident management process, but also provides an interface into many other IT processes.

Service request.

Requests for new or altered service. The types of service requests vary between organizations, but common ones include requests for information (RFI), procurement requests, and service extensions. Requests for change (RFC) may also be included as part of service request.

Solution.

Also known as a permanent fix. An identified means of resolving an incident or problem that provides a resolution of the underlying cause.

Workaround.

An identified means of resolving a particular incident, which allows normal service to be resumed, but does not actually resolve the underlying cause that led to the incident in the first place.

Backout plan.

A documented plan detailing how a specific change, or release, can be undone after being applied, if deemed necessary.

Change advisory board (CAB).

The CAB is a cross-functional group set up to evaluate change requests for business need, priority, cost/benefit, and potential impacts to other systems or processes. Typically the CAB makes recommendations for implementation, further analysis, deferment, or cancellation.

Request for change (RFC).

The formal change request, including a description of the change, components affected, business need, cost estimates, risk assessment, resource requirements, and approval status.

Operating level agreement.

An internal agreement with support IT functions, supporting the SLA requirements.

Operating level objective.

Objectives within an operating level agreement that indicate the measures to be reported in the operational environment. The operating level objectives are aligned to the service level objectives.

Service.

A business function deliverable by one or more IT service components (hardware, software, and facility) for business use.

Service catalog.

A comprehensive list of services, including priorities of the business and corresponding SLAs.

Service level agreement.

A written agreement documenting the required levels of service. The SLA is agreed on by the IT service provider and the business, or the IT service provider and a third-party provider.

Service level management.

The process of defining and managing through monitoring, reporting, and reviewing the required and expected level of service for the business in a cost-effective manner.

Service level objectives.

Objectives within an SLA detailing specific key expectations for that service.

Service level agreement review.

The operations management review for service level management. Also referred to as the SLA Review. This involves reviews of the SLAs and performance against objectives, and a review of previous and potential issues that may affect services.

Underpinning contract.

A legally binding contract, in place of or in addition to an SLA . This contract is with a third-party service provider on which service deliverables for the SLA have been built.