The types of SLA metrics needed depend on the services provided. Many elements can be monitored as part of an SLA, but the scheme should be as simple as possible in order to avoid confusion and excessive costs on both sides. When selecting metrics, look at how you`re working and decide what`s most important. The more complex the monitoring scheme (and associated mitigation system), the less likely it is to be effective, as no one has time to properly analyze the data. When in doubt, opt for a simple collection of metric data. Automated systems are the best, as expensive manual recording of metrics is unlikely to be reliable.