In PRM, the total collection of processing resources is divided into subsets which correspond usually to administrative domains. Each such subset is managed by a system manager (SM) which is responsible to allocate its resources to jobs as needed. The system managers themselves can be organized in a hierarchical manner in order to avoid bottlenecks and ensure scalability.
The system manager maintains information about the characteristics of each resource it is responsible for, together with the mapping from resources to jobs assigned to them. The system manager receives status updates from node managers (e.g. availability, load information) and uses them to make allocation decisions. The system manager also responds to resource requests from job managers.