Managing changes for knowledge-intensive processes like System and Software Engineering is a critical issue but far from being mastered due to the lack of supporting methods and practical tools. To manage changes systematically, a process environment is needed to control processes and to handle changes at run-time. However, such an effective environment satisfying these requirements is still missing. The reason is two-folds: first, operational process environments for system and software engineering is scarce; second, there is a lack of efficient change management mechanism integrated in such process environments. In order to address these concerns, we aimed at developing a change-aware process environment for system and software engineering. To this aim, we proposed a change management mechanism based on (1) the Process Dependency Graph (PDG) representing the dependencies among running process instances managed by a process environment ; (2) a Change Observer process to catch change events and update the PDG with run-time information; (3) a Change Analyzer component to extract the impacts of change by reasoning the PDG. In terms of implementation, to gain the benefits from the Business Process Community, where many mature Business Process Management Systems have been developed, we chose jBPM to enact and monitor processes. The key strengths of this study are: first, the PDG makes hidden dependencies among process instances emerge at run-time; second, the process observer inside the BPMS allows to handle the change events in a timely manner. Finally, the Neo4j graph database, used to store the PDG, enables efficient traversal and queries.