To extract abstract views of the behavior of an object-oriented system for reverse engineering, a body of research exists that analyzes a system's runtime execution. Those approaches primarily analyze the control flow by tracing method execution events. However, they do not capture information flows. We address this problem by proposing a novel dynamic analysis technique named Object Flow Analysis, which complements method execution tracing with an accurate analysis of the runtime flow of objects. To exemplify the usefulness of our analysis we present a visual approach that allows a system engineer to study classes and components in terms of how they exchange objects at runtime. We illustrate and validate our approach on two case studies.