Lean Software Development: An Agile Toolkit is written by Mary and Tom Poppendieck. The principles of lean software development are used in more ways than just in manufacturing. Turiba University’s Department of Business Administration report that 73% of companies under study saw improvement in product quality by adopting a lean system. Lean development highlights actions that don’t bring improvement to the final product or the process as a whole. Lean suggests that software devs assign manageable tasks and ensure their completion before handing out more.