So the first false assumption that underlies the scheduling of systems programming is that all will go well, i.e., that each task will take only as long as it "ought" to take. The pervasiveness of optimism among programmers deserves more than a flip analysis. Dorothy Sayers, in her excellent book, The Mind of the Maker, divides creative activity into three stages: the idea, the implementation, and the interaction. A book, then, or a
