Service Level Agreement (SLA) is usually a contract between a customer and a
service provider, e.g. a provider of an information system or telecommunication
services. The SLA contract most commonly defines:
Requested service scope
Level of service capacity and availability
Prices and also fees in case of breaching the negotiated service scope or level
The service level offered by the provider is usually presented as a percentage,
where e.g. a guarantee of 99.9 % availability means a potential service
breakdown of 8 hours and 46 minutes per year.