Business Continuity Planning for Mathematicians...

There’s a mathematician’s joke (yes, mathematicians do actually have jokes) which goes like this:

1. Given an empty kettle, running water, a teapot, and a tea bag, how does a mathematician make tea? He fills the kettle with cold water, boils the kettle, pours the boiling water into the teapot, adds a tea bag, waits three-and-a-half minutes, then pours the tea.
2. Given an kettle full of boiling water, a teapot, and a tea bag, how does a mathematician make tea? He empties the kettle, thus reducing the problem to one that has already been solved. QED.

I’m reminded of this joke when I read some business continuity plans. A common recommendation in the industry is to plan for the worst possible case. You should, so the advice goes, plan for the worst thing that could happen (your building being totally destroyed) and plan for it happening at the worst time of year (during the Christmas rush, or just before an SEC filing).

It sounds like a good idea: if you can survive the worst possible disaster, then you must be able to survive a lesser (but more probable) disaster. But it’s potentially an expensive one.

If the plan only deals with the worst possible case, then it is rather like the mathematician making tea. The only course of action open is to pretend that the worst possible case has occurred, resulting in an expensive and possibly time-consuming response and recovery.

A good plan should have the flexibility to be useful in a variety of circumstances. No incident will exactly happen as planned and some types of incident are more likely than others.

A good plan should provide the information required to react to the situation as it is, rather than the worst possible incident that might have occurred.