Semiconductor Tool OEE Calculator

Quantify overall equipment effectiveness for lithography, etch, deposition, or metrology tools by combining uptime, takt adherence, and yield loss into a single percentage. Enter the planned production window, unplanned downtime, ideal cycle time, and output counts to diagnose where capacity is slipping away.

Scheduled tool time for the shift or campaign, excluding planned shutdowns.
Leave blank to assume zero unplanned stops. Include maintenance, faults, and setups you treat as losses.
Benchmark takt time per wafer or lot under nominal conditions.
Lots or wafers started in the window, including scrap.
Leave blank to treat all units as good output; enter lots or wafers scrapped or sent to rework.

Manufacturing diagnostic aid; confirm KPIs with your factory MES or analytics platform before reporting externally.

Examples

  • Planned 24 h, downtime 2 h, ideal cycle 180 s, 400 wafers with 12 scrap ⇒ Availability 91.67%, Performance 90.91%, Quality 97.00%, OEE 80.83%.
  • Planned 10 h, downtime left blank, ideal cycle 90 s, 360 lots, no scrap ⇒ Availability 100.00%, Performance 90.00%, Quality 100.00%, OEE 90.00%.

FAQ

Should planned maintenance be included?

Exclude scheduled maintenance or engineering time from planned production hours so availability only reflects unexpected loss.

What if the tool runs multiple product recipes?

Use the appropriate ideal cycle time for the recipe mix in the window—either a weighted average or the slowest takt if you want conservative performance.

How do I handle rework loops?

Add reworked wafers back into the total units so the performance factor captures the extra load; count only finally accepted wafers as good output.

Additional Information

  • Result unit: % OEE with component percentages shown for availability, performance, and quality.
  • Cycle time is converted from seconds per unit to an hourly throughput benchmark inside the calculation.
  • Scrap defaults to zero if left blank so the quality factor equals 100%.

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