SKEDSOFT

Design for Maintainability

Maintainability:

Probability that a failed component or system will be restored or repaired to a specified condition within a specified period of time when maintenance is  performed in accordance with prescribed procedures

Quantifiable measures:

• Mean time to repair

• Median time to repair

• Maximum time in which a certain percentage of the failures must be repaired

• Mean system downtime

• Mean time to restore

• Maintenance work hours per operating hour

Design process determines conditions under which maintenance and repair are to be accomplished

• Which units are to be repaired rather than discarded and replaced

• Preventive maintenance schedule and associated tasks

• For repairable units, the level of repair (such as local, service center, or factory) for each failure mode

• For each repair task, the required skill levels, tools, test equipment, and technical manuals

• The number of repair channels and spare parts (inventory)