Abstract:

Buffer monitoring is a core content of critical chain project management， which can control the project progress by monitoring the project buffer. In the research of critical chain project buffer monitoring， most of them monitor the project in units of activities， stages or projects， and the measurement of project progress is not comprehensive. Earned value management and schedule risk analysis theory analyze and control the project schedule from the whole and part， respectively， but there are still some limitations in measuring the activity and project schedule risk when applied to buffer monitoring research. In order to comprehensively analyze the overall progress and internal activity information of a project， and provide more effective early warnings of project execution during the buffer monitoring process， a new sensitivity index and monitoring threshold are established based on the schedule risk analysis and the earned duration theory， and an all-round buffer monitoring model is proposed in this paper. First， considering the network and resource characteristics of activities， as well as the impact of the mean and standard deviation of the duration on project progress， an integrated sensitivity index based on simulation is established to measure activity risks and allocate the buffer. Second， the monitoring threshold is determined according to the earned duration method incorporated by the sensitivity index， and then differential deviation corrective measures are taken for activities with different risks to form a comprehensive buffer monitoring system. The new sensitivity index reflects the impact of activity risk on the project from bottom to top， and the improved monitoring threshold provides overall top-down control from a project perspective， thus forming a comprehensive buffer monitoring system. Finally， the proposed method， static buffer monitoring method and relative buffer monitoring method are applied to a typical tailings pond construction project to carry out Monte Carlo simulation. The results show that compared with classical methods， the proposed method has double optimization effects in shortening the duration and reducing the cost， which verifies the feasibility and effectiveness of the proposed method. It can help project managers to comprehensively analyze the progress of the project from the perspective of project and activity， and provide a certain reference value and practical significance for the decision-making of project progress control.

Key words: critical chain project management, buffer monitoring, schedule risk analysis, earned duration method, monitoring threshold