This paper has explored when implementing SW development project of the IT service corporations, what factors affect its productivity in SW development methodology. The importance of the AHP analysis surveyed from the experts in IT service companies and related committee, was shown in the order of the following processes : 1) Deployment process 2) Management process 3) Establishment process. It is measured the methodology levels of establishment, deployment and management in each project using the survey results collected from project execution members and analyzed the productivity of projects that have been executed within 2 years. Using project methodology level, productivity correlation analysis, and regression analysis, this study confirms that the methodology deployment level brings positive effects significantly to SW development productivity. The significance of this study would be not only to research and analyze SW development productivity using the real project execution data but also to underline the necessities and the importance of steady research, deployment and support for SW development productivity improvement.