Reliability or Availability?

One can understand that organizations trying to improve efficiency of their operations focus on the Reliability of their systems and equipment.

It seems to me that it would be even better if the organizations focus on Availability instead.

Availability of a system is defined by Bloch and Geitner as the fraction of time the system is able to function. Availability is then a function of the failure rate and the time to repair; in other words, Reliability and Maintainability.

Availability= Uptime/(Uptime+Downtime)

In certain circumstances the return of investment on marginal Reliability enhancements discourage improvements while the organization may be missing opportunities to improve Availability by making improvements to Maintainability. Formula One teams do not focus on making tires last the entire race (Reliability), instead they focus on minimizing the time it takes to change the tires during the race (Maintainability).

Next time you are involved in an activity aimed to improve Reliability ask yourself if the actual objective is to improve Availability. If that is the case, ask the team to include Maintainability as a possible path in the scope of the improvement.