Scheduling
Total scheduled production time for the shift, before any downtime is removed.
Downtime
Scheduled breaks, planned maintenance, team meetings.
Equipment breakdowns, material shortages, operator absence.
Production
The theoretical fastest time to produce one part (from equipment spec or time study).
Parts meeting quality spec without rework. Leave blank to assume all parts are good.
Financial (Optional)
Optional. Used to calculate the financial value of lost production.
OEE Trend (Last 5 Shifts)
Enter OEE % for your last five shifts to visualize the trend.
Enter Production Data
Fill in planned production time, downtime, cycle time, and parts produced to calculate your OEE score and uncover hidden capacity losses.
How to Use This OEE Calculator
Choose Your Input Mode
Select Simple Mode if you already have Availability, Performance, and Quality percentages from your MES or tracking sheet. Select Detailed Mode to enter raw production data — the calculator will compute all three component percentages automatically.
Enter Your Production Data
In Detailed Mode, start with a shift preset (8-hour, 10-hour, or 12-hour) to auto-fill Planned Time and Planned Downtime. Then enter Unplanned Downtime (breakdowns), Ideal Cycle Time (from equipment spec), Total Parts Produced, and Good Parts. Use the time unit and cycle time unit selectors to match your tracking data.
Review OEE Score and Breakdown
The results panel shows your OEE score as a color-coded progress ring alongside individual Availability, Performance, and Quality percentages. The stacked bar chart visualizes how each loss category consumes your planned production time. The Hidden Factory section shows how many additional good parts you could produce per shift.
Export or Track Trends
Enter OEE values from your last five shifts in the Trend section to visualize performance over time. Click Export CSV to download a full results summary for your production records, or use Print to generate a clean shift handover report.
Frequently Asked Questions
What is a good OEE score?
The widely accepted benchmark for world-class OEE in discrete manufacturing is 85%, a standard established by the Japan Institute of Plant Maintenance (JIPM). This accounts for realistic break schedules and minor operational variability while still representing excellent equipment performance. A score of 60% is considered typical for most manufacturers — many facilities start OEE tracking here and use the gap to 85% as their improvement target. Scores below 40% indicate significant losses across multiple categories and usually signal an urgent need for TPM or lean improvement activity. Process industries (chemicals, food, pharmaceuticals) sometimes use different benchmarks due to continuous-flow production characteristics.
What is the difference between planned and unplanned downtime in OEE?
Planned downtime covers events that are scheduled and expected before the shift begins — such as team meetings, breaks, planned preventive maintenance, and scheduled changeovers. In most OEE frameworks, planned downtime is excluded from Planned Production Time before Availability is calculated, meaning it does not penalize the OEE score. Unplanned downtime is any stop that was not anticipated: equipment breakdowns, tooling failures, material shortages, or operator absence. This is the first of the Six Big Losses and directly reduces Availability. Separating the two types helps teams distinguish between a scheduling issue and a reliability issue when diagnosing root causes.
Why can Performance exceed 100%?
Performance greater than 100% usually means the Ideal Cycle Time entered is too conservative — the machine is actually capable of running faster than the theoretical maximum you specified. This can happen if the ICT was set from an old standard that predates equipment upgrades, or if operators have found a way to run faster than the spec. It can also indicate a data entry error. The OEE formula will produce a Performance value above 100%, and consequently an OEE above the apparent maximum. To fix this, re-measure your actual fastest sustainable cycle time and update the ICT input. The calculator will warn you when Performance exceeds 100%.
What is the Hidden Factory?
The Hidden Factory is the additional production capacity that already exists in your equipment but is consumed by OEE losses. It represents the good parts you could have produced if every loss had been eliminated. The concept was popularized by OEE.com and evocon.com to make the cost of poor OEE tangible. For example, if you produce 900 good parts per shift but your equipment could theoretically produce 1,600, the hidden factory is 700 units — production you are paying for in fixed costs but not capturing as revenue. This calculator quantifies it precisely and, if you enter a revenue per unit value, converts it to a dollar amount per shift.
What are the Six Big Losses?
The Six Big Losses is a framework that classifies all sources of OEE loss into six categories. Availability losses include (1) Equipment Failure — unplanned breakdowns, and (2) Setup and Adjustments — planned changeovers and calibration. Performance losses include (3) Small Stops — brief pauses and jams that are not recorded as formal downtime, and (4) Reduced Speed — running below the Ideal Cycle Time. Quality losses include (5) Startup Rejects — defects produced during machine warm-up, and (6) Production Rejects — defects during the normal production run. By categorizing your losses this way, you can identify which of the three OEE factors needs attention and assign the right improvement methodology.
What is the difference between OEE and TEEP?
OEE measures effectiveness relative to Planned Production Time — the time the equipment was actually scheduled to run. If a machine is only scheduled for one eight-hour shift per day, a 90% OEE still leaves 16 hours of calendar time unused. TEEP (Total Effective Equipment Performance) extends the denominator to 24 hours per day, 365 days per year, capturing the impact of scheduling decisions as well as equipment losses. A facility with 90% OEE on a single shift might have a TEEP of only 30%, reflecting the large amount of calendar time where no production is even attempted. OEE is used for operational improvement; TEEP is used for strategic capacity planning and capital investment decisions.