Off-Site Construction Planning Using Discrete Event Simulation

Abstract

Off-site construction has become an inseparable part of many construction projects and can increase the productivity and quality of construction projects. Off-site construction involves the application of a significant portion of the required operations to construction elements by off-site fabrication shops in a more controlled and equipped work environment before delivery of the elements to the construction site for erection or assembly. Unfortunately, capturing the constraints imposed by the erection (i.e., assembly) sites in addition to the internal constraints applied to the fabrication shops can make the planning process of fabrication shops challenging for construction managers. To address this issue, the use of discrete event simulation (DES) is proposed as an effective tool for modeling the operational details involved in construction, including constraints arising from both the erection process and from off-site fabrication shops. The applicability and usefulness of this method has been investigated in an experimental case of steel construction; DES models of an off-site structural steel fabrication of a girder bridge project were developed to assess different fabrication plans and to reduce the final project’s duration, and an approximate 10% potential reduction of the final project duration through adjusting the fabrication plan alone was demonstrated.