Lean Construction Planning Subject to Variations in Detailed Features of Fabricated Bridge Girders

With the growing implementation of prefabrication and off-site construction in practice, the focus of job shop scheduling shifts from manufacturing to the practical application context in construction. This research explores a new lean approach to project planning and scheduling assisted with production operations planning by simulation. The research methodology uses a simulation model that had been developed to account for sufficient details from the perspective of the actual shop manager and thoroughly validated in collaboration with an industry partner. A simulation case of planning bridge girder fabrication at a steel fabrication shop was conducted to illuminate on ‘mura’ (variations in product design and production process) inherent in girder fabrication. Based on the simulation, we made an attempt to elaborate the inherent variations in girder fabrication time and inter-girder lag in order to facilitate applying lean concepts in planning bridge construction projects.