For component-based systems, classical techniques forWCET-estimation produce unacceptable overestimations ofthe WCET. This is because software components have moregeneral behavior in order to support reuse. Existing toolsand methods for component-based software engineering(CBSE) do not yet adequately consider reusable analyses.We present a method that allows different WCETs to beassociated with subsets of the component behavior by clusteringWCETs with respect to behavior. The method is intendedto be used for facilitating reusable WCET analysisfor reusable software components. We illustrate ourtechnique and demonstrate its potential in achieving tightWCET-estimates for components with rich behavior.