The assembly of the modular housing is an important phase in the construction of pre-fabricated houses. However, the assembly tools that are commonly used in a work site have a disadvantage of decreasing the productivity and the quality. We have developed a exclusive tool for assembling modular parts. The structural stability of the developed tool has been verified in the previous studies. However, the experimental analysis was not conducted. This study analyzed the effect of improving the productivity and quality of the developed assembly tool. The result of the experimental analysis shows improvements in productivity and quality compared to the conventional assembly tool.