How does OEE corrected for cavitation differ from standard OEE?

OEE corrected for cavitation is standard OEE multiplied by the cavitation factor. It shows the real combined effectiveness of the mold and the machine — without this correction, an organization may not see that part of the output drop comes directly from the number of active cavities, not from downtime or quality.

Is the OEE calculator free?

Yes, the tool is fully free, with no limit on the number of cavitation periods, no registration and no installation.

Online OEE Calculator with Mold Cavitation — Free Tool

Q: What is injection mold cavitation in the context of OEE?

Mold cavitation is the number of cavities forming a part simultaneously in one injection cycle. When some cavities get blocked, plugged or deliberately deactivated, the mold produces fewer parts per cycle than its full specification assumes — and standard OEE metrics usually don't show this loss separately.

Q: Why don't standard OEE calculators account for cavitation?

The classic OEE formula (Availability × Performance × Quality) was built for single-output processes, where one machine cycle yields one part. In multi-cavity processes like injection molding, the loss from incomplete cavitation blends into other losses and disappears in the overall result — which is why this calculator tracks it as a separate, visible factor.

Q: How is the cavitation factor calculated?

The cavitation factor is a duration-weighted average, across every production period, of the ratio of active cavities to total mold cavities. If an 8-cavity mold ran with 8 active cavities for half the shift and 6 for the other half, the factor is 87.5%.

Q: Is my data stored in the cloud?

No. The calculator runs entirely in the browser and stores the data you enter locally (localStorage) on your device. Nothing is sent to any server.

Short answer

With today's technology, you don't need to invest millions to calculate OEE effectively and know which machine on the floor needs attention first. This calculator computes standard OEE, plus — as the only tool of its kind available online — a separate cavitation factor: the time-weighted ratio of active mold cavities to total cavities. The final result is real effectiveness, not just a number that hides the loss from an incomplete mold.

Why cavitation is a separate loss, not part of Performance or Quality

The classic OEE formula was built for processes where one machine cycle yields one part. In multi-cavity processes — injection molding being a typical example — one cycle can yield anywhere from a few to dozens of parts at once, depending on the number of cavities in the mold. When some cavities get blocked, plugged, or deliberately deactivated (e.g. pending repair), the machine keeps running its cycle, but produces fewer parts than the mold's full specification assumes.

That loss disappears somewhere inside the standard OEE formula — it blends into Performance or Quality depending on how the input data happens to be counted. The result: the team sees OEE drop, but can't see directly how much of that drop is cavitation versus real downtime or quality defects. This calculator separates the two.

What the calculator computes

Standard OEE — Availability, Performance and Quality calculated from classic inputs (planned time, downtime, ideal cycle time, total cycles, parts produced and good parts).
Cavitation factor — a separate, visible number: a duration-weighted average of the ratio of active cavities to total mold cavities across consecutive periods of a shift.
OEE corrected for cavitation — standard OEE multiplied by the cavitation factor: a real picture of machine and mold effectiveness combined.
Multiple periods per shift — add as many rows as the number of times the active cavity count changed (e.g. a cavity got blocked mid-shift).
Print and PDF export — directly from the browser.
Data stays local, no cloud — the data you enter is saved in the browser (localStorage) and never sent anywhere.

How the metrics are calculated

AvailabilityOperating time ÷ Planned production time

Performance(Ideal cycle time × Total cycles) ÷ Operating time

QualityGood parts ÷ Total parts produced

Standard OEEAvailability × Performance × Quality

Cavitation factorΣ(period duration × active cavities) ÷ (total mold cavities × Σ period duration)

OEE corrected for cavitationStandard OEE × Cavitation factor

A spreadsheet handles part of these questions well — quality analysis, for instance, since defects can simply be counted. A system built on standard cycle time treats any time above it as a micro-stop, which lets you catch parameter drift during production and observe process instability before it grows into a real problem. This calculator adds the missing piece: mold cavitation as a separate, measurable loss.

Open the calculator

Below is the working application — you can enter your process data right away. The demo version comes pre-filled with sample data, which you can freely overwrite or clear.

How to get started (3 steps)

Step 1

Enter base OEE data

Planned production time, downtime, ideal cycle time, and the number of cycles and parts (produced and good).

Step 2

Enter cavity count and cavitation periods

Enter the total number of mold cavities, then add one row for every time the active cavity count changed.

Step 3

Read the result

Standard OEE, the cavitation factor and corrected OEE are calculated automatically, live.

How to interpret the result

Cavitation factor close to 100% — the mold runs with almost its full cavity count; the cavitation loss is minimal.

Cavitation factor well below 100% — a real, measurable loss from blocked or deactivated cavities — worth checking the cause on the gemba.

Standard OEE high, corrected OEE low — the problem lies in the mold (cavitation), not the machine or work organization.

Standard and corrected OEE close together — cavitation isn't currently the main issue; look for losses elsewhere.

Frequently asked questions

What is injection mold cavitation in the context of OEE?

The number of cavities forming a part simultaneously in one cycle. When some cavities get blocked or deactivated, the mold produces fewer parts per cycle than its full specification.

Why don't standard OEE calculators account for cavitation?

The classic OEE formula was built for single-output processes. In multi-cavity processes, the loss from incomplete cavitation blends into other losses and disappears in the overall result.

How is the cavitation factor calculated?

A duration-weighted average, across every period, of the ratio of active cavities to total mold cavities.

How does corrected OEE differ from standard OEE?

It's standard OEE multiplied by the cavitation factor — showing the real combined effectiveness of the mold and machine.

Is my data stored in the cloud?

No — the data stays locally in the browser (localStorage), nothing is sent to a server.

Is the calculator free?

Yes, fully free, no limits, no registration and no installation.

Online OEE Calculator with Mold Cavitation — the only tool of its kind