work smart, not hard

Why Crunch Mode Doesn't Work: 6 Lessons

by Evan Robinson

Lesson One, then, is this: Productivity varies over the course of the
workday, with the greatest productivity occurring in the first four to
six hours. After enough hours, productivity approaches zero;
eventually it becomes negative.

Lesson Two, then is this: Productivity is hard to quantify for
knowledge workers.

Lesson Three is this: five-day weeks of eight-hour days maximize
long-term output in every industry that has been studied over the past
century. What makes us think that our industry is somehow exempt from
this rule?

Lesson Four is this: At 60 hours per week, the loss of productivity
caused by working longer hours overwhelms the extra hours worked
within a couple of months.

Lesson Five is this: Continuous work reduces cognitive function 25%
for every 24 hours. Multiple consecutive overnighters have a severe
cumulative effect.

Lesson Six is this: Error rates climb with hours worked and especially
with loss of sleep . Eventually the odds catch up with you, and
catastrophe occurs. When schedules are tight and budgets are big, is
this a risk you can really afford to take?

http://www.igda.org/articles/erobinson_crunch.php