Chart 53 of Techniques of Systems Analysis shows how not to do contingency planning:
It does, we admit look at three different contingencies, a small, medium, and large attack. It shows how best to allocate the defense budget if any of these attacks occurs and what the performance will be with any allocation and its corresponding attack. The first time we saw a chart like this, it was called contingency planning, but this is definitely a misnomer.
The reason is shown on Chart 54, which give the contingency analysis of the planning of Chart 53. It shows, for example, that, if one plans for a heavy attack and a small one actually materializes, he could have done 35% better if he had planned correctly. Similarly, if one plans for the small attack and the large one materializes, he could have done 67% better.
While looking at a chart like this is a step in the right direction, it is not enough. It is very common in discussion of Systems Analysis to have people come up with such a chart and then ask, “What do you do? How do you choose between these systems?” This attitude is more than a little wrong.
It implies that one has a rather small range of choices and that the big job is somehow to decide among these choices. This is essentially impossible to do satisfactorily in this extreme case because people have different estimates of what the circumstances are likely to be. The main job of a good Systems Analyst is to design a system that will be satisfactory in all reasonable contingencies. He should spend most of his time trying to make the decision problem less agonizing rather than on the decision problem itself. In fact, it is fair to say that a good way to measure success in designing a system is on how unagonizing one has made this choice problem.