Flow-based software development (FSD, aka “lean”, pull-based, or kanban) put focus on improving flow of work items (normally software features) through a software development work process. But what does it mean in practice? We show the nitty-gritty of how to set up a project to run flow-based instead of timebox-based, and when it makes sense to do so. We show a simple KPI model to better capture the state of a project using FSD, and how it can be used as a basis for conducting experiments aimed at process improvements.

Experimentation is one way to gain insight into how processes perform for a team, but teams rarely do experiments, fearing such educational excursions will incur extra costs and cause schedule overruns. When facing a stalemate concerning pair programming, one team performed a lightweight experiment evaluating pair programming and programming alone with inspection. Through the experiment, the team learned that pair programming was faster than programming alone, required less effort, and had more predictable quality. Lightweight experimentation is easy, cost effective, and fun.