Software process improvement (SPI) today is based mainly on a perception of software processes as artifacts and this perception has led SPI efforts to focus on perfecting such artifacts as a means to improve the practices of the people supposed to execute these software processes. Such SPI efforts thus tend to view the design of software processes as separate from their use. In this approach process designers are expected to provide process knowledge to software developers, and software developers are expected to provide experiences and problems to the process designers. This focus on software processes as artifacts implies an emphasis on formalization and externalization of process models possibly at the expense of the process knowledge in the heads of the process users. The paper point to problems related to separation and externalization from a theoretical standpoint and suggests an alternative to Improvement by Design: End-user SPI, where process users individually and collectively design their own software processes assisted by process experts.