In recent years, research in the field of business processes has shown a shift of interest from the activity-centric perspective to the artifact-centric one. The benefits, such as improved communication among the stakeholders and higher potential for flexibility, come from the focus on the key business entities (called artifacts) and on the distribution of the control flow in the life cycles of the artifacts. However, this perspective also entails a number of challenges, such as the coordination between the life cycles of the artifacts. This paper proposes an approach based on correlated transitions, i.e., transitions that belong to different life cycles and must be performed jointly. A new notation called Acta is illustrated with the help of two motivating examples.