Glossary
What is Downtime?
Downtime is the period when an asset, line or system is not available for use—whether due to failure, maintenance or other reason. Unplanned downtime is often caused by failures; planned downtime is scheduled for maintenance or other work.
What it means
Reducing unplanned downtime is a key goal of preventive and predictive maintenance. Downtime is often recorded in work orders and used in KPIs like MTBF and availability.
Why it matters
- Unplanned downtime: asset is down due to failure or unexpected event.
- Planned downtime: scheduled for PM, repairs or other work.
- Availability = (total time − downtime) ÷ total time, often expressed as a percentage.
- Recording downtime causes in work orders helps identify recurring issues.
Example in maintenance operations
A production line stops for 4 hours due to a conveyor motor failure (unplanned downtime). The same line is shut for 2 hours the following week for scheduled bearing replacement (planned downtime).
Related concepts
Frequently asked questions
How do you reduce unplanned downtime?
Preventive maintenance, condition monitoring and quick response to defects can reduce unplanned downtime. Recording and analysing causes in a CMMS helps target improvements.
Run maintenance with VectraManage — work orders, PM and reporting in one platform
See pricing Start free