Planning and feed back loop in Extreme Programming with time frames
<a href="//commons.wikimedia.org/wiki/User_talk:Ayacovlev" title="User talk:Ayacovlev">Ayacovlev</a>
CC BY-SA 3.0
Own work based on: <a href="//commons.wikimedia.org/wiki/File:Xp-loop_with_time_frames.svg" title="File:Xp-loop with time frames.svg">Xp-loop with time frames.svg</a> <i>by</i> <a href="//commons.wikimedia.org/wiki/User:Mdd" title="User:Mdd">Marcel Douwe Dekker</a>