Learn in the textbookFundamentals of Service Management and Service Level Management
DefinitionAn SLA (service level agreement, サービスレベル合意書) is a document in which the service provider and the customer set out the scope of the service and the level of quality to be provided.
ExplanationFor example, it states in numbers the hours when the service can be used and how long recovery from a failure may take. Putting this in writing gives the provider and the customer the same understanding of what the service includes and what level is expected. The management activity of maintaining and raising the agreed level is called service level management (サービスレベル管理, SLM).
AnalogyIt is like booking a banquet hall and fixing the hours, the number of guests, and the menu in the written reservation.
Memory hookThe final A stands for Agreement.