CNC OEE Software
OEE is easy to calculate and easy to get wrong. CNC OEE software measures run and stop time straight from the machine, so the number reflects what happened — and shows you the stops behind it.
Overall Equipment Effectiveness answers one question: of the time you planned to make parts, what share actually became good parts at full speed? It multiplies three losses together:
- Availability — did the machine run when it was supposed to?
- Performance — when it ran, did it run at its ideal cycle?
- Quality — were the parts good the first time?
A machine at 90% availability, 90% performance, and 98% quality has an OEE of about 79%. That sounds healthy until you realize 21% of the shift — roughly 100 minutes of an eight-hour day — produced nothing usable.
OEE is only as honest as its inputs. Software earns its keep by measuring stop time and part counts from the machine instead of from memory — and by showing the stops that make up every lost point.
Why spreadsheet OEE goes wrong in CNC shops
Most shops that "track OEE" fill in a spreadsheet at the end of the shift. The math is right. The inputs are not.
- Stops get rounded. A 7-minute wait for a tool becomes zero. Twelve of them become an hour nobody can find.
- Planned time is fuzzy. Was the 30-minute setup planned? Was lunch? Different people answer differently, so last month's 68% and this month's 72% are not comparable.
- Ideal cycle times are guesses. If the ideal is set from the quote, performance looks great because the quote was padded.
- It arrives late. End-of-shift OEE tells you what went wrong after it is too late to fix it.
CNC OEE software solves the first and last problems automatically and makes the other two explicit settings you decide once.
How FEAI Machine Monitor calculates OEE
FEAI Machine Monitor reads machine state and production signals through MTConnect and builds a timeline for every machine.
| OEE factor | Where the data comes from | What you configure |
|---|---|---|
| Availability | Running vs stopped vs idle time on the machine timeline | Which shifts and hours count as planned production |
| Performance | Part count and cycles reported by the machine, compared with ideal cycle time | An ideal cycle time per machine (seconds) |
| Quality | Good parts vs total parts | Reject counts when you record them |
Because the timeline is minute-by-minute, every OEE number can be opened up. A drop from 71% to 63% on Tuesday is not a mystery — it is three long idle windows on second shift and a slow program on one part family, and you can see each of them.
What good OEE software shows you
OEE by machine, shift, and day. The headline number, broken down so you can compare like with like.
The loss breakdown. Of the points you lost, how many were availability (stops), performance (slow cycles), or quality (rejects)? This tells you which team owns the problem: scheduling and maintenance for availability, programming and tooling for performance, process and inspection for quality.
The stops behind availability. Ranked by total minutes and by frequency. One 90-minute breakdown and thirty 3-minute waits need very different fixes.
Trends. Did the change you made last week move the number this week? OEE that is not tracked over time is just a grade.
OEE, utilization, and availability — which one should you watch?
These three get confused constantly.
| Metric | Formula | Best for |
|---|---|---|
| Utilization | Run time ÷ available time (calendar or scheduled) | Capacity planning, "do we need another machine?" |
| Availability | Run time ÷ planned production time | Measuring stop losses during planned work |
| OEE | Availability × Performance × Quality | Measuring total effectiveness of planned time |
For high-mix job shops, many owners start with utilization and availability because they are intuitive and need no ideal cycle times. OEE becomes valuable once you have stable ideal cycles for your repeat parts. FEAI shows all three from the same data. Use the machine utilization calculator to see the difference with your own numbers.
Setting ideal cycle times without fooling yourself
Performance is the most manipulated factor in OEE. A few rules keep it honest:
- Use the best proven cycle, not the quoted cycle. If the machine has run the part in 84 seconds, the ideal is 84, not the 95 you quoted.
- Set it per machine and part family where you can. A high-mix shop can start with a typical cycle per machine and refine for repeat jobs.
- Watch for performance over 100%. It means the ideal is too slow. Fix the setting rather than celebrating.
- Revisit after program improvements. When programmers cut a cycle, the ideal moves too.
A realistic OEE improvement path
- Week 1–2: measure. Connect machines and leave the numbers alone. Resist the urge to explain them away.
- Week 3: agree on definitions. Planned time, what counts as a planned stop, and ideal cycles for top parts.
- Week 4 onward: attack the biggest availability loss. It is usually waiting — material, programs, first-article inspection, or operator coverage — rather than breakdowns.
- Then performance. Look for programs running well below their best cycle and for feed overrides left turned down.
- Quality last for most CNC shops, because scrap rates are usually lower than stop and speed losses.
Track the trend weekly. A few points of OEE on a bottleneck machine is worth more than a large gain on a machine that waits for work anyway. Learn the math in detail with our OEE calculator and formula guide.
OEE for job shops vs production lines
Classic OEE was built for high-volume lines running one part for weeks. Job shops change jobs constantly, which creates two traps:
- Setup time. Decide whether setups are planned stops (excluded from availability) or losses (included). Many shops include them, because setup reduction is one of the biggest wins available.
- Changing ideal cycles. With dozens of part numbers a week, per-part ideals are hard to maintain. Start with machine-level availability and utilization, then add performance for your top repeat parts.
FEAI Machine Monitor is built for this kind of shop: local Windows software, pay by machine, and useful even before every ideal cycle is perfect.
Pricing
OEE is included on every plan, including Free.
| Plan | Machines | Monthly |
|---|---|---|
| Free | 2 | $0 |
| Shop | 5 | $99 |
| Growth | 10 | $199 |
| Scale | 25 | $399 |
| Pro | 50 | $699 |
Measure your real OEE
Connect two machines free and see your actual availability, performance, and stops within a week. Start free — 2 machines.
FAQ
What is a good OEE for a CNC machine?
Benchmarks often quote 85% as world class, but most job shops with high-mix, low-volume work run well below that. A realistic first goal is to measure your own baseline accurately and improve it a few points at a time. Compare a machine with itself over time rather than with a generic benchmark.
How does software calculate OEE automatically?
Availability comes from planned time minus stop time on the machine timeline. Performance compares actual parts against what the ideal cycle time would allow in the run time. Quality uses good parts versus total parts when rejects are recorded.
Do I need MTConnect for OEE software?
FEAI Machine Monitor uses MTConnect. Your machine must provide accessible MTConnect data through an MTConnect Agent or compatible endpoint. Part count and execution state are the most important data items for OEE.
Why is my performance over 100%?
The ideal cycle time is set slower than the machine actually runs. Set it to the best proven cycle for the part rather than the quoted or estimated time.
Is OEE the same as utilization?
No. Utilization is the share of time the machine was running. OEE also penalizes slow cycles and bad parts, so OEE is always equal to or lower than availability.
Can I get OEE software free?
Yes. FEAI Machine Monitor includes OEE on the Free plan for up to 2 machines.