A Service Level Agreement may also define:
- Milestones and Key Performance Indicators (KPIs) that are to be achieved,
- the service and the service level to be provided
- how performance under the agreement will be monitored and controlled.
The term SLA is sometimes used to refer to the contracted delivery time (of the service) or performance.
There is a good description of achieving Service Levels in the IIMM - the International Infrastructure Management Manual in Section 3.1.