Continuous improvement of software development capability is fundamental for organizations to thrive in competitive markets. Nevertheless, Software Process Improvement (SPI) implementation based on software process reference models and standards is a complex and long-term endeavor that requires investment of large sums of money. This paper describes a national program for SPI in Brazilian organizations. The main goal of this initiative is to develop and disseminate a Brazilian software process model (named MPS Model) aiming to establish a feasible pathway for organizations to achieve benefits from implementing SPI at reasonable costs, especially SMEs. This paper presents the main components of MPS Model. The results of MPS Model adoption and dissemination in Brazilian software industry are also presented in this paper. Although the main focus of the MPS Model is on SMEs, the model demonstrated to be adequate to support SPI implementation and assessment in large organizations.