External Insulation Finishing System (EIFS) is recognized as a suitable method for attaining energy efficiency of buildings. However, conventional EIFS is not actively applied to building construction due to additional time and cost compared with interior insulation method. Therefore, as an alternative that can contribute to active utilization of the external insulation system, this study proposes an External Insulated Precast Concrete (PC) Wall System and its simulation for performing productivity analysis. Results of this study are as follows: (1) an external insulated PC-Wall system is developed of which its insulation performance is above 40% higher than that of the conventional EIFS; (2) performance of the developed system satisfied American Standards for Testing of Materials (ASTM) and American Architectural Manufacturers Association (AAMA) standards; (3) applicability of the developed system is verified via test-bed with construction time lapsing about 40 min for each PC-Wall; and (4) CYCLONE modeling methodology is employed to perform productivity analysis of the developed system compared with conventional EIFS.