Abstract: Given the fact that real-time monitoring of a project being implemented is impossible for managers, we propose a periodical project buffer monitoring method. The new method fully considers the shortage of setting warning threshold for real-time buffer monitoring, and proposes the concept of monitoring cycle in the field of buffer monitoring. The proposed method predicts the probability of active state and transition based on Markov chain, then takes reasonable emergency measures according to the activity state transition situation, and determines the optimal monitoring period with the lowest total activity cost and the shortest activity duration as the optimization objective. The Monte Carlo simulation experiment is eventually carried out to validate the model system. The results show that, as opposed to the classic buffer monitoring methods, the proposed method can effectively improve the robustness of a project in response to emergencies, avoid the waste of monitoring resources and cost, and highlight the monitoring focus, thus achieving the double optimization of project duration and cost under the premise of guaranteeing the completion probability.

Key words: project management, critical chain, buffer monitoring, monitoring period, Markov chain