Due to globalization and increase in the level of technology requirements, managing expectation and customer demand for software development projects becomes more challenging. Therefore, the notion of quality and productivity gain importance for software development. In order to improve the quality and productivity, CMMI capability model has been widely adopted within software development organizations. This paper presents an overall software efficiency improvement project, which is implemented within the scope of organizational performance management which covers all process areas of CMMI level 5. Within the scope of the project, our organization targeted software productivity increase and it is achieved by improving code creation productivity of the organization. The result of the paper can be a reference for other organizations in software development industry seeking to improve software productivity by using the level of CMMI 5 maturity.