Incorporating QoS specifications in service discovery

In this paper, we extend the current approaches to service discovery in a service oriented computing environment, such as Web Services and Grid, by allowing service providers and consumers to express their promises and requirements for quality of service (QoS). More specifically, we allow service providers to advertise their services in an extended DAML-S that supports quality specifications, and we allow service consumers to request services by stating required quality levels. We propose a model here for incorporating QoS specifications and requirements in service discovery, and describe how matchmaking between advertised and requested services based on functional as well as quality requirements is supported in our model