The behavior of concurrent, real-time systems can be specified using a process algebra called CCSR. The underlying computation model of CCSR is resource-based, in which multiple resources execute synchronously, while processes assigned to the same resource are interleaved according to their priorities. CCSR allows the algebraic specification of timeouts, interrupts, periodic behaviors and exceptions. This paper develops a natural treatment of preemption, which is based not only on priority, but also on resource utilization and inter-resource synchronization. The preemption ordering leads to a term equivalence based on strong bisimulation, which is also a congruence with respect to the operators. Consequently the equivalence yields a compositional proof system, which is illustrated in the verification of resource-sharing, producer-consumer problem.