The aim of the chapter is to describe how service-level agreements (SLAs) could be utilized to provide the basis for resource trading based on economic models. SLAs enable a service user to identify their requirements, and a provider to identify their capabilities. Subsequently, the terms in an SLA are necessary to ensure that mutually agreeable quality is being delivered by the provider according to the agreement. The use of service-level agreements (SLAs) in a resource management system to support Grid computing applications is described. To this end, we provide an architecture that supports the creation and management of SLAs. The architecture of the system, in terms of the components and their interactions, is first presented, followed by a description of the specific requirements for a marketoriented Grid economy. We use SLAs as a means to support reliable quality of service for Grid jobs. The creation of such an SLA requires planning and orchestration mechanisms. We will discuss these functionalities and also consider the economic aspects such as dynamic pricing and negotiation mechanisms. These mechanisms are necessary to enable SLA formation and use, and to ensure that an SLA is being adhered to during service provision.