A Simple Way to Estimate the Cost of Downtime

Systems that are more dependable and less expensive to maintain may be more expensive to purchase. If ordinary customers cannot calculate the costs of downtime, such systems may not succeed because it will be difficult to justify a higher price. Hence, we propose an easy-to-calculate estimate of downtime.

As one reviewer commented, the cost estimate we propose ``is simply a symbolic translation of the most obvious, common sense approach to the problem.'' We take this remark as a complement, noting that prior work has ignored pieces of this obvious formula.

We introduce this formula, argue why it will be important to have a formula that can easily be calculated, suggest why it will be hard to get a more accurate estimate, and give some examples.

Widespread use of this obvious formula can lay a foundation for systems that reduce downtime.