Calculating, detecting, observing, and validating operating characteristics, conditions, and metrics, especially quality of service metrics, of a system. The quality of service metrics are reported and utilized to manage the service. The various elements of the system for generating the quality of service metrics are integrated, with the same or substantially the same schema and metadata in the databases management systems of the externalized metric configuration data database, and the raw transaction data database. There is extensive code reuse, with the various engines, as the standard requirements methodology engine and thee standardized extensible calculation engine utilizing the same classes or objects, and as appropriate, the same function calls, interfaces, api's, and the like.