Designing software processes for large enterprises is a hard task, but evolving this process can be even harder. As large companies increasingly invest in software process improvement, they have to face typical problems regarding software process evolution within such environments in order to guarantee their software process survival. This article describes experiences and lessons learned at Serpro, the largest government owned software company in Latin America, while defining its organizational standard software process and fostering its continuous evolution. Copyright © 2008 John Wiley & Sons, Ltd.