Oee Availability
OEE Availability is the percentage of Planned Production Time that equipment is actually running, calculated as Run Time ÷ Planned Production Time. It measures uptime losses only, excluding performance speed and quality defects.
In shop floor maintenance, OEE Availability is tracked via CMMS systems like ServiceGrid by logging downtime events such as failures and changeovers against the scheduled production window. Planned Production Time excludes pre-arranged stops like breaks and weekends, while Run Time excludes all unplanned stops and setup delays. A 100% score indicates continuous operation during scheduled time with zero stoppages, making it critical for identifying and reducing downtime losses.
- Unplanned Equipment Failures: Mechanical breakdowns like bearing seizures or motor failures that halt production unexpectedly.
- Extended Setup/Changeover Times: Poorly managed adjustments or tooling swaps that exceed standard time, consuming planned production time.
- Ignoring Micro-Stops: Failing to log short interruptions under 5 minutes that cumulatively devastate availability but are often dismissed as operator issues.
How does OEE Availability differ from Reliability Availability (A(T))?
OEE Availability uses Planned Production Time as the baseline; Reliability Availability uses Total Time (uptime + downtime) over a mission period.
What are the 'Six Big Losses' affecting Availability?
Equipment Failures (unplanned) and Setup/Adjustments (planned).
Can Quality defects impact OEE Availability?
No; Quality is a separate OEE factor. Availability strictly measures time lost to stops, not defective output.
Formula nuance: Is Run Time = Planned Time – Downtime?
Yes; Availability = (Planned Run Time – Downtime) / Planned Run Time.