Collaborative Buffer Monitoring and Control of Critical Chain Multi-Projects Considering Cross-Level Risk-Sharing Effect

Buffer monitoring is critical for managing uncertainty and risk in projects. In the multi-project environment, various buffers coexist within critical chains, yet traditional monitoring methods mainly focus on individual buffers, overlooking their hierarchical associations. This study first analyzes the cross-level risk-sharing effect caused by buffer coexistence. Next, we determine the extractable project buffer capacity and allowable buffer consumption at the project level using the activity cruciality index. These project-level buffers are transferred to the system level, where the allowable capacity of the constraint buffer is calculated based on project dependency. Finally, dynamic monitoring trigger points are set to adjust for real-time changes in buffer consumption, enabling a collaborative monitoring system for coordinated buffer control. Experimental results demonstrate that, compared to the traditional method, the proposed approach reduces sub-critical chain delays, improves response validity for drum activities, and shortens the overall system critical chain duration, resulting in less buffer waste and increased control efficiency in the multi-project environment.