Compositional performance analysis iteratively alternates local scheduling analysis techniques and output event model propagation between system components to enable performance analysis of heterogeneous distributed systems. In spite of its high scalability and adaptability, the compositional approach may suffer from overestimated results compared with other system performance verification techniques. The main reason is an incomplete consideration of event sequence correlations. In this paper we present a new technique that improves the output jitter calculation by correlating jitter and response times and offers significantly tighter analysis bounds.