In construction projects, contingency reserves have traditionally been estimated based on a percentage of the total project cost, which is arbitrary and, thus, unreliable in practical cases. Monte Carlo simulation provides a more reliable estimation. However, works on this topic have focused exclusively on the effects of aleatoric uncertainty, but ignored the impacts of other uncertainty types. In this paper, we present a method to quantitatively determine project cost contingency reserves based on Monte Carlo Simulation that considers the impact of not only aleatoric uncertainty, but also of the effects of other uncertainty kinds (stochastic, epistemic) on the total project cost. The proposed method has been validated with a real-case construction project in Spain. The obtained results demonstrate that the approach will be helpful for construction Project Managers because the obtained cost contingency reserves are consistent with the actual uncertainty type that affects the risks identified in their projects.

翻译：在建筑工程中，应急储备金传统上基于项目总成本的百分比进行估算，这种方法具有随意性，因此在实际情况中并不可靠。蒙特卡洛模拟提供了更可靠的估算方法。然而，该领域的研究仅关注随机不确定性的影响，而忽略了其他类型不确定性的作用。本文提出了一种基于蒙特卡洛模拟定量确定项目成本应急储备金的方法，该方法不仅考虑了随机不确定性的影响，还考虑了其他类型不确定性（偶然性、认知性）对项目总成本的影响。所提出的方法已通过西班牙的一个实际建筑工程案例进行了验证。结果表明，该方法对建筑工程项目经理具有实用价值，因为所得出的成本应急储备金与影响其项目已识别风险的实际不确定性类型相一致。