capability for the OS to elect the running processes among the set of ready toi run processes

capability for the OS to associate a subset of CPUs to execute a given process and its threads

capability for the OS to improve the priority of a process to avoid interlocking

capability for the OS to alter the priority of a process depending on its past usage of resources

capability for the OS to ensure the least priority process will alwais have a chance to use the CPU

capability for the OS to replace a running task by another according to preemption rules or scheduling priorities