What Is Availability in OEE? EDGEBIC Definition

Availability is the OEE factor that measures lost time: the share of a machine's scheduled hours in which it was actually running. In EDGEBIC by User Solutions, availability is actual hours divided by available hours, where available hours come from the shift definition multiplied by calendar days and the instance count. A machine scheduled for 40 hours that ran only 32 has 80 percent availability. The number captures every reason the machine was not making parts when it should have been: breakdowns, holidays, an unrun shift, or a long changeover.

This entry is part of the EDGEBIC glossary series. For the wider planning vocabulary, see the manufacturing glossary. Availability is the first of the three factors that multiply into overall equipment effectiveness; the other two are performance rate and quality rate.

How Availability Works

OEE breaks equipment losses into three buckets, and availability owns the time bucket. It asks a single question: of the hours this machine was scheduled to run, how many did it actually run?

EDGEBIC builds the denominator, available hours, from the calendar rather than a guess. It takes each active shift's total hours, multiplies by the number of calendar days in the window, and multiplies again by the machine's instance count. Where no shifts are configured, it falls back to 8 hours times the number of workdays times instances. The numerator, actual hours, comes from the daily hour breakdown that actuals logging fills in as work happens.

Divide one by the other and you have availability, capped at 100 percent so an over-logged machine cannot report an impossible number. Everything that stopped the scheduled time from turning into run time (a breakdown, a public holiday inside the window, a shift that did not run) lands in the gap between available and actual hours and drags availability down. That is why availability is the honest first read on whether a machine is dependable, before you even ask how fast or how cleanly it ran.

A Concrete Example

Take CNC-1 over a Monday to Friday window, a single 08:00 to 16:00 shift (8 hours a day), one instance.

Available hours:

• 8h per shift times 5 days times 1 instance = 40 available hours

The daily hour breakdown records 32 actual hours, because only 4 of the 5 days ran:

• Availability = minimum of (100, 32 divided by 40 times 100) = 80 percent

The reading: CNC-1 was available 80 percent of the time and lost a full day, 20 percent, most likely to a holiday or a breakdown. In the same window the machine ran at about 86 percent of theoretical throughput and 95.5 percent quality, giving an OEE near 65.5 percent. Of the three factors, that 20 percent availability loss is the biggest single lever for lifting the machine's OEE, which is exactly the kind of steer the number is meant to give a supervisor.

How EDGEBIC Uses Availability

Availability is a column in EDGEBIC's OEE report, next to performance percent, quality percent, and the composite OEE. It is derived per work center for the date range you choose, drawing available hours from the shift and instance configuration and actual hours from the daily hour breakdown. The walkthrough in how to run the OEE report in EDGEBIC shows the full column set and how the three factors combine.

One point to keep straight: availability is not utilization. Utilization, in the Work Center Utilization report, asks how much of a machine's capacity was booked with scheduled work. Availability asks whether the scheduled work actually ran. A machine can look busy in the utilization view yet score low on availability because breakdowns stopped the plan from happening. Reading them together tells you both whether the machine is loaded and whether it is reliable, and that pairing is where OEE earns its place on a supervisor's scorecard.