Percentile analysis can be performed in both short term forensics and long term service providing trending. Any Percentile analysis can be calculated.
Most commonly known for its benefit in Billing as 95th Percentile it also has a large benefit for security and alerting.
For example a burst may occur once or may occur in ever increasing frequency. A percentile analysis of a threshold event will provide an indication of change. This should be used in conjunction with Baseline analysis.