Most of the tasks of the knowledge worker require, for minimum effectiveness, a fairly large quantum of time. To spend in one stretch less than this minimum is sheer waste. One accomplishes nothing and has to begin all over again.
To write a report for instance, requires 6 to 8 hours at least for the first draft. It is pointless to give 7 hours to the task by spending 15 minutes twice a day for three weeks. All one has at the end is a blank paper with some doodles on it. But if one can lock the door, disconnect the telephone, and sit down to wrestle with the report for 5 or 6 hours without interruption, one has a good chance to come up with what I call a “zero draft” – the one before the first draft…
To be effective, every knowledge worker and especially every executive needs to be able to dispose of time in fairly large chunks. To have small dribs and drabs of time at his disposal will not be sufficient even if the total is an impressive number of hours.