Service Level Agreement (SLA) (ITILv3):    [Service Design] [Continual Service Improvement] An Agreement between an IT Service Provider and a Customer. The SLA describes the IT Service, documents Service Level Targets, and specifies the responsibilities of the IT Service Provider and the Customer. A single SLA may cover multiple IT Services or multiple Customers.

See also: TBD

Cross Reference: Agreement

Service Level Agreement (SLA) (ITILv2):    A formal, negotiated document that defines (or attempts to define) in quantitative (and perhaps qualitative) terms the service being offered to a Customer. Confusion must be avoided over whether the quantitative definitions constitute thresholds for an acceptable service, targets to which the supplier should aspire or expectations that the supplier would strive to exceed. Any metrics included in a Service Level Agreement (SLA) should be capable of being measured on a regular basis and the SLA should record by whom. Typically it will cover: service hours, service availability. Customer support levels, throughputs and responsiveness, restrictions, functionality and the service levels to be provided in a contingency. It may also include information on security, charges and terminology.

Apart from regular periodic reviews, SLAs should be renegotiated whenever a business service is subject to a change of requirement or there is an inability to deliver to requirement.

See also: Agreed Service Time, Agreement, Service Level Management, Service Management

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An SLA is best described as a collection of promises. The document records the promises, but not the means or details of execution. While it may contain costs for services, i.e. charging, the primary location to discover charges is the service catalogue, formerly known as the menu of services. The actual structure is dependent on the organization type and activity which might take the perspectives of service, customer, or multi-level agreements. However, the general structure of the agreement is:

You might wonder why the contract is before the details, because it does not follow the structure we expect. Most contracts includes signatures at the end of the document along with the words: this is the entire agreement. In the words of those who created the structure, they wanted people to look at the SLA and immediately identify the responsible parties.

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