A Hybrid Framework for Modeling Construction Operations Using Discrete Event Simulation and System Dynamics

Construction projects are characterized by their dynamic nature and operational details. This paper presents a hybrid simulation methodology; designed to model construction projects. The methodology utilizes Discrete Event Simulation (DES) and System Dynamics (SD). DES has been widely used in modeling construction operations; however, it lacks the ability to model the global aspects of operations being modeled and the cause-effect relations of simulation variables. SD is utilized to circumvent these limitations. Both simulation methods provide valuable decision support but none is individually capable of capturing the holistic nature of the operation being modeled. The developed methodology integrates DES and SD to utilize their respective advantages in simulating construction operations. The developed methodology encompasses five stages: 1) identification of model objectives, 2) decision criteria to assist in selecting simulation methodology, 3) building simulation model and identification of interface variables, 4) computation framework and 5) implementation and testing. The paper describes the essential features of the developed methodology and its computational framework and focuses primarily on the modeling aspects of SD. A case study project is analyzed to demonstrate the use of the developed methodology and to highlight its capabilities. INTRODUCTION Construction projects are dynamic and subject to randomness. They involve many interoperations, which include context, operations and resource interactions (AbouRizk and Hague 2009). Numerous strategic and operational decisions are made over a project’s lifecycle. These make prediction of construction project performance a complex and challenging task for project managers. The construction environment is a diverse physical environment characterized by cost and schedule overruns, uncertainty and the dynamic nature of construction (Chan et al. 2004). Simulation is widely regarded as an effective tool for analysis of construction operations because of its ability in handling the complexity and uncertainty inherent in construction processes (Halpin et al. 2003). In construction, computer simulation modeling is used for the purpose of monitoring the system in a controlled 1063 Construction Research Congress 2012 © ASCE 2012