Bracket supported R/C Downward (BRD) method is an advanced construction method which is free from using supports, short pillars propping up a veranda floor. It allows placing concrete downward by gradually descending slab forms which are united with gird and beam forms. BRD method descents the slab forms which are suspended by threads using brackets and bracket attachment apparatuses. It maximizes the cost saving and the reuses of equipments relative to BRD form by reusing them as many as the numbers of the basement stories. This paper presents a simulation model that facilitates to model and analyze the productivity of BRD operation. By conducting motion and time study, resource processes of the operation and their tasks of the processes are defined. These atomic tasks are used as a building block to implement a simulation model that reflects the real world BRD operation on the job site. The model contributes to improve productivity of the operation by identifying the optimal resource combination and the productivity delay factors in BRD operation. A case study is implemented to verify the usability and validity of the system in practice.