I just finished Peter Druker's classic "The Effective Executive" and he really strongly emphasizes the need to throw out the old: "The first rule for the conce

I just finished Peter Druker's classic "The Effective Executive" and he really strongly emphasizes the need to throw out the old: "The first rule for the concentration of executive efforts is to slough off the past that has ceased to be productive. Effective executives periodically review their work programs—and those of their associates—and ask: 'If we did not already do this, would we go into it now?' And unless the answer is an unconditional 'Yes,' they drop the activity or curtail it sharply." Drucker, Peter F.. The Effective Executive (Harperbusiness Essentials) (p. 115).