I&#x27;ve found that teams (and individuals) function best when tasks are either scope-delimited or time-delimited.  Not both, and not neither.  If the task is concrete enough that the desired outcome is crystal-clear and there&#x27;s not much risk in completing it, then just say &quot;It&#x27;s done when it&#x27;s done&quot; and let someone work at it.  If the task has fuzzy success criteria - &quot;Make this UI better&quot;, for example, or &quot;speed this up as much as you can&quot;, or &quot;explore new approaches for this module&quot; - <i>put a deadline on it</i>.  It&#x27;s possible to spin your wheels forever if you don&#x27;t have a clear destination and clear timeframe.