Construction Schedule Risk Analysis Based on Complex System Theory: Methodology and Empirical Study

With the development of China’s society and economy, a large number of construction projects are being actively carried out. Project schedule, as one of the major concerns in construction projects, is always affected by high uncertainties and risks brought by the substantial amount of human and nonhuman factors. Therefore, more prominence should be given to proposing effective measures to minimize the losses caused by schedule risks. Although a certain progress has been made from the previous studies, the lack of dynamics and uncertainty analysis lead to results different from reality. This study aims to propose a novel model for analyzing construction project schedule risk. On the basis of complex systems theory, this paper builds a system dynamics model, and encapsulates the system dynamics model into discrete event simulation to form “work module” which can be combined according to the requirements of different projects, Monte Carlo simulation is also employed to analyze the uncertainty of risks. In addition, a WeChat platform is established for collecting schedule risk data. Finally, the present model is validated by a case study after the structure test and behaviors test. The results showcase that: (1) System dynamics can effectively deal with the complex problems of project schedule from the perspective of system, which includes rework, quality problems, the allocation of resource, productivity, decision-making delays, schedule pressure, etc. (2) It greatly improves the applicability of the model to combine system dynamics and discrete event simulation together. (3) Monte Carlo simulation enables the model to obtain the distribution of real-time planned duration in the process of construction, and to be suitable for managers with different risk attitudes and risk-bearing capacity to make decisions.