We developed a quality of service (QoS) management system to support service level management (SLM) for global enterprise services. The QoS management system is integrated with one of our enterprise services in a preproduction system, an identical system as the production system but in a test environment. Lab experiments showed that our integrated solution helps global enterprise services to better maintain the service level agreements. Test results have validated our architecture design and integration approach. This paper describes our QoS management architecture and its integration within the enterprise service system with a focus on QoS monitoring, diagnostics and adaptation. We will also present the validation test results as a case study in this paper.