Project production flows in off-site prefabrication: BIM-enabled railway infrastructure

Railway infrastructure projects provide required physical and organizational facilities for transportation networks. Production flows in railway construction are complex especially when a hybrid of on-site and off-site processes is in progress. With railway projects still experiencing budget and time overruns, there is need to re-examine production flows. Towards this aim, a framework to investigate production flows in railway infrastructure projects is presented and discussed. A three-dimensional view of construction production including portfolio, process and operation aspects is found capable of improving performance measures in both design and construction. Such improvements include minimized rework and re-entrant flows, flexible prefabrication, enhanced multidisciplinary collaborations, and efficient planning of temporary works. This research contributes to the construction body of knowledge by examining production flows in a complex infrastructure setting. Construction managers would benefit from the presented model of production flows and its customization in the context of their projects to improve productivity and performance.