With business environments constantly changing, organisations and individuals must execute and learn in parallel to ensure they can solve today's problems and plan for tomorrow's. This action research explores how action learning can improve Software Process Improvement (SPI) success by 'improving the improvers'. The strategy is to engage SPI teams in theory studies and relate these studies to daily work to help them critically reflect on practice improvements. SPI change agents at Ericsson AB in Gothenburg, Sweden, took on this challenge, participating in a year-long action learning effort. This study presents detailed data about that effort and its impact on the organisation's SPI success rate. Four action-learning activities literature studies, workshop participation, SPI project meetings, and one-on-one coaching serve as a lens to understand and assess the effort's value. The data suggests that action learning is a useful approach for improving SPI change agents' understanding and reflection capabilities, thereby increasing the SPI success rate.