How to achieve greater productivity of teams

Well said.

He actually said 35 hours. 40 hours is the number for manual work (at Ford's).

Another key finding is that your subjective impression of productivity will be wrong if you exceed 35 hours per week. You'll think you're more achieving more even as you dip below the average productivity.

For the more Machiavellian among us, he also claims you'll be rewarded by management more on appearance of productivity (i.e. long hourse) than on actual results.

I have an actual horror story about a colleague's acquaintance which proves him right:

(1) On a late project, with only 3 weeks away from delivery, a manager (the above acquaintance) was called to save the day. He found that the team was on crunch mode, and quite tired.

(2) First day, at 18 O'clock, he said "Everyone go home, I don't want to see you until 9am tomorrow". He actually made it a policy.

(3) Projects miraculously ships on time and on budget (or at least, it slipped far less than originally expected, I don't remember).

(4) The team is happy. The manager's bosses are not, on the ground that if the team worked harder (read: longer hours), it would have performed better. As a result, they didn't gave him any more responsibilities.

Clearly, as Dan Pink said, "there is a mismatch between what science knows, and what business does".