Simulating Uncertainties in Construction Projects with Chronographical Scheduling Logic

The more complex a project, the more attractive nontraditional project delivery methods like design-build or fast-tracking become with these delivery methods and uncertainty has to be explicitly integrated into the network calculations. Uncertainties assess levels of compliance with various constraints. This paper contributes to the existing body of knowledge by modeling diverse types of execution uncertainties, such as construction operation, execution process, and work with doubtful results, and by extending the traditional logic and modeling uncertainties using the chronographic time-scaled, point-to-point relations, production-based dynamic relations, and function dependencies between in-progress activities. The dependencies between activities can be related to the external scale (usually representing time) or an internal scale (usually representing quantity). Using the Monte Carlo simulation, the paper simulates the impact of construction operations, execution processes, and work with doubtful results. For companies, this approach represents scheduling constraints in a flexible manner and provides a feasible solution for modeling the complexity of real-world projects. - See more at: http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29CO.1943-7862.0001212#sthash.lcospyaI.dpuf项目复杂度越高，设计-施工（design-build）或快速跟进（fast-tracking）这类非传统项目交付模式便越具吸引力；且采用此类交付模式时，不确定性因素必须被显式整合进网络计划计算流程中。不确定性用于评估各类约束条件的合规程度。本文通过对多样化的执行不确定性类型进行建模（涵盖施工作业、执行流程及结果存疑的工作等），并拓展传统逻辑，采用基于时间刻度的时序（chronographic time-scaled）点对点关系、基于生产的动态关系以及进行中活动间的函数依赖关系来对不确定性进行建模，从而为现有知识体系贡献新的研究成果。活动间的依赖关系可关联至外部尺度（通常代表时间）或内部尺度（通常代表工程量）。本文采用蒙特卡洛模拟（Monte Carlo simulation）方法，模拟了施工作业、执行流程及结果存疑工作所带来的影响效应。对于企业而言，该方法能够以灵活的方式表征进度约束条件，并为真实工程项目的复杂特性建模提供可行解决方案。 - See more at: http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29CO.1943-7862.0001212#sthash.lcospyaI.dpuf