I argue that lean software development firms become more productive if they adopt and align lean managerial accounting systems with lean software development processes. I conduct two experiments on retraining and coaching of software development teams that have used lean and agile software development practices, demonstrating that these practices significantly improve productivity compared to control groups that did not receive this retraining and coaching. In a third experiment, I expand on this theme by introducing lean accounting productivity metrics to a treatment group of software developers. Team leaders actively use these metrics as quantitative “retrospectives” in team meetings to review past performance and identify areas for process improvement. Four months after these metrics are introduced, I measure their impact on the treatment group productivity and also survey the group to determine how these metrics affect employee attitudes and productivity compared to a control group that was not trained in use of these metrics for team meetings. The results indicate that introduction of lean accounting metrics does not impact employee attitudes and understanding of processes and metrics, nor does it improve productivity in the near term. Discussions with management indicate that retraining and coaching immediately improve productivity since they are directed at remedying specific operational and process issues. Using lean accounting metrics to impact team productivity and employee attitudes is more foundational and likely requires a longer period of exposure and learning. The experimental site is a large publicly traded software firm that uses lean and agile software development practices. Key Words: Lean Accounting, Training, Coaching, Software Development, Productivity