In prefabricated construction projects, unlike stick-built construction projects, structural components are produced in a factory environment. Thus, similar to manufacturing industries, the productivity of building components fluctuates, owing to human errors and machine malfunctions. Since the site demand must always be met, outsourcing manufacturing is employed to supplement the uncertain self-production. Furthermore, storage facility between factory and construction site becomes indispensable because these components are large in size, yielding a three-tier supply chain that is absent in the traditional construction. The objective of this research is to determine the most appropriate production plan and the optimal outsourcing quantities for multi-prefabricated components under this context. A workflow which includes a two-stage stochastic programming model and a mixed integer linear programming model is established for solving the above issues. Also, the most favourable schemes for distributing components and the variation of inventory are also disclosed. An infrastructure built through prefabrication method was selected as a case study to validate the models