Metrics is measurement.
Specifically it is the measurement of specific criteria or factors that relate to business operations, performance, quality, reliability, etc. The goal of the activity is to present an accurate picture of the measured environment.
Establishment of a metrics program requires the definition of the performance indicators to be measured, the desired performance levels, the sources of data, the best data sources, the statistically appropriate calculation methodologies, and the results presentation structure.
Whether the focus of the metrics program is to verify service levels provided by a vendor or internal services, the result is the same: verification of service levels or quality and timeliness of provided service. In that sense, a well designed and developed metrics program can improve the operating environment, reduce costs due to improved service levels and, in situations where vendors do not improve service levels, document the case for service termination and replacement.