Definition
Maintainability is a measure of how easily and quickly a failed asset can be restored to a functioning condition, under defined conditions and with defined resources, influenced by design factors such as accessibility, modularity, and diagnosability, as well as available skills, tools, and spare parts. It is distinct from reliability, which addresses how rarely the asset fails in the first place.
Key facts
- Addresses ease and speed of restoration after failure, not the probability of failing in the first place.
- Influenced by design (accessibility, modularity, standardized fasteners) as much as by maintenance organization (skills, tools, spare parts).
- Typically expressed in terms of expected repair time under stated conditions, such as MTTR for a defined population of failures.
- One of the two components, alongside reliability, that combine into availability.
What does Maintainability reveal about failures?
Maintainability measures how readily a failed asset can be restored (reflecting both physical design factors like component accessibility and modularity, and organizational factors like technician skill, tool availability, and spare-parts readiness) typically expressed as an expected repair time under stated conditions.
How do teams use Maintainability in failure analysis?
Reliability addresses how rarely an asset fails; maintainability addresses how quickly it can be fixed once it does. MTTR is one specific metric that measures maintainability in practice for a defined set of failures, calculated as total repair time divided by number of repairs.
FAQ
Frequently asked questions
What makes an asset easily restorable or maintainable?
Maintainability: a combination of design factors (accessibility, modularity, diagnosability) and maintenance-organization factors (technician skill, tool and spare-parts availability) that determine how quickly a failed asset can be restored to function.
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