AGILE IN ACTION

The prevailing management (and financial) mindset in companies today is focused on efficiency, productivity, and costs. The primary concern is to maximize all assets and capabilities so that nothing sits idle. What this really means is keeping people working at 100% utilization.

Slack isn't waste, it's spare capacity or buffering. Shit happens, so having room to react, maneuver and adapt when something unexpected occurs can help protect deadlines (to a degree) and avoid potential catastophes. Tom DeMarco refers to this room as Slack . Kent Beck has added a practice called slack to Extreme Programming Edition 2 that advocates including some minor tasks in each iteration, which can be de-scoped if the team falls behind. I've also used slack as a feature buffer comprising low priority user stories. In Lean Development waste is typically any of the following: Partially done work Extra processes Extra features Task switching Waiting Motion Defects The practice of slack reduces waste because it helps to avoid partially done user stories. Partially done user stories are waste because they have no business value precisely because they are incomplete.

Michael Feathers identified iteration slop as the time spent before an iteration, preparing for it, and the time spent after an iteration, finalizing the work.