Value stream mapping is a valuable tool in the lean toolbox that truly uncovers hidden waste in a process. Recent researches have focused on process improvement in various construction domains, but more research need to address precast concrete operations at the plant. This paper seeks to investigate the integration of lean principles in the fabrication phase of modular construction by using value stream mapping. The research focuses on the plant processes used to produce precast concrete pre-slabs and on means of improvement. It presents results from a case study of Company X’s precast plant. Data describing the current state of pre-slab casting was collected from plant visits, the current value stream map is drawn, and a future state map is then recommended. Indeed, alongside some effective lean concepts that are applied at the plant such as preventive maintenance and autonomation, some weaknesses are identified such as sizeable raw material storage, large batch sizes, considerable final product inventory and lack of “shine”. Appropriate remedial measures are recommended such as reducing batch and inventory size, creating FIFO lanes as well as applying 5S across the plant.
Value stream mapping, lean principles, modular construction, precast operations