Early and rigorous performance analysis of component-based systems is a crucial issue in software engineering to guarantee that the developed components and their assemblies will satisfy their quality requirements. We propose an original approach, called the CB-SPE, for component-based software performance engineering. CB-SPE relies on, and adapts to a CB framework, the concepts and steps of the SPE technology and uses for modeling the standard RT-UML profile, reshaped according to the CB principles. The approach is compositional in that it is applied first at the component layer for achieving parametric performance evaluation of the component in isolation, and then at the application layer for predicting the performance of the assembled components on the actual platform. We also outline the architecture of a tool supporting the automation of the proposed approach, and overview related work.