Components fail and equipment is lost even when planners have a mean time to failure. With many examples of a component in service, an unexpected failure somewhere can itself be predictable. The average does not identify which individual part will need replacement. Supply work must accommodate that uncertainty as well as accidental damage or loss by the people using the equipment.
Notable Point · 1:43:42-1:44:40
Why average failure rates do not identify the next missing spare
A fleet-wide expectation of failures still leaves uncertainty about which component will fail first.