Abstract: Considering the influence of maintenance on reliability, an approach about the modeling of failure processes for repairable systems was presented, which includes the definition and formulation of failure rate. Interrelations between these rates and failure intensities, such as inherent hazard rate and failure intensity, were also discussed. To get some maintenance and repair policies of repairable systems, the formula and trend diagrams of failure rate were derived. All of these lead to an approach to the analysis of failure rate for repairable systems.