This paper describes a Quality of Service (QoS) management approach and architecture as well as a case study for Service Level Management (SLM). Our approach brings in a new perspective to the SLM probem by using QoS management and QoS Contract specification, establishment, and monitoring. In SLM, the service consumer side and the service provider side must share a common understanding of QoS characteristics and use a common language for specifying desired QoS parameters in the form of QoS contracts. A service consumer must negotiate with the service provider to establish mutually agreed QoS contracts for an interaction session. When establising a new QoS contract, the service provider must consider both QoS contracts already agreed upon with existing consumers and system resource conditions. Similarly, a service consumer must be prepared in revising its contract with the service provider as conditions change over time. Once a QoS contract is established, SLM must monitor QoS status t...