This paper describes a computer system having quality of service data available the moment decision makers need it. To manage Quality of Service, France Telecom uses a customized system which provides decision makers with statistical information and performance indicators to evaluate quality performance, diagnose dysfunctions, analyze cause and effect relations, set forecasting goals and plan actions. This automized statistical information system contains monthly Quality of Service data related to different layers of management (regions, business units, exploitation units) during a four year period. The historical data is saved for other specific applications. The Quality of Service information system is put on line for different types of telecommunication users: executives, top managers, middle managers, front-line managers, experts and consultants.