[whpalmer4]

Another consideration from a real-life perspective is that if your task is X hours of work over Y months, it's unlikely that work on the task will be uniformly accomplished at X/Y hours/month, especially if that works out to be some small percentage of the resource. Much more likely than someone spending exactly 17 minutes each day for months is that there will be bursts of intense activity, and stretches with little or no activity. The planning exercise is useful for totting up the total utilization of a resource over some period, so the temptation to add "just one more" 5% task to the resource that already has 20 such assignments can be more easily resisted, but it has to be remembered that progress will be lumpy, as any given day is likely to be 5 tasks worked at 20% (and 15 left fallow) rather than 20 tasks worked for exactly 24 minutes each :-)