Sources of Loss in Manufacturing: How OEE HelpsIdentify Them
Every manufacturing operation experiences losses. These aren't always dramatic breakdowns or long downtimes — sometimes losses are hidden in the small things:slow start-ups, micro-stoppages, repeated operations. They’re hard to notice, but over time they drain productivity, time, and money.
That’s where OEE comes in. It doesn’t just show overall efficiency — it breaks it down into components, helping you pinpoint the exact sources of loss.
Why Losses Matter More Than Absolute Efficiency
The OEE score itself won’t "heal" your production process. But it plays a crucial diagnostic role. Just as a doctor starts with checking your temperature, OEE helps "measure the health" of your production line.
Losses are what silently erode your profits — even if everything seems to be running fine. OEE helps you uncover, classify, and eliminate them.
Types of Losses According to OEE
Traditionally, all losses are grouped into three categories, matching the three components ofOEE:
1. Availability Losses
What it is:
Time when equipment should be running, but isn’t.
Common causes:
- Breakdowns and failures
- Setup and changeovers
- Material shortages
- Waiting for operator or logistics
How to detect it:
Track downtimes. Even frequent 10-minute stops are a warning sign. In OEE, theydirectly reduce the Availability score.
Tip: Log thereasons for all stops — even short ones.
2. Performance Losses
What it is:
Equipment is running, but slower than it should.
Common causes:
- Micro-stoppages (5–30 seconds, often unnoticed)
- Operating below rated speed
- Worn-out tools
- Inexperienced operators
- Operator fatigue
How to detect it:
Compare actual performance with the ideal cycle time. Even small speed reductions mean loss.
Tip: Use sensors or software to detect every stop longer than 1–2 seconds.
3.Quality Losses
What it is:
Time and resources spent producing defective or reworked items.
Common causes:
- Incorrect setup parameters
- Poor raw material quality
- Process instability
- Human error
- Tooling issues
How to detect it:
Track the ratio of good to total units. OEE counts only the first-pass quality output.
Tip: Include not just scrap but also rework — that’s loss too.
What Losses Look Like on an OEE Diagram
Imagine 100% as perfect time utilization. Now subtract the losses:
- Availability losses – equipment is stopped
- Performance losses – equipment is running, but too slow
- Quality losses – equipment is working, but making defects
What’s left is your true “productive time” — a fraction of the full shift.
Extended View: The 6 Big Losses of TPM
The Japanese TPM (Total Productive Maintenance) model expands OEE into six types of loss:
This model allows for deeper analytics and visual breakdowns of losses by type.
Why This Kind of Analysis Matters
It focuses on causes, not symptoms
Instead of a vague “this machine is inefficient,” you’ll see: “90 minutes a day are lost to setup time.”
It aligns the team around facts
Engineers, operators, and managers all look at the same data and make decisions together.
It enables improvements without investment
Reducing downtime or micro-stops improves output without needing to buy new equipment.
Conclusion: OEE as a Tool for Hunting Losses
OEE is not just a number on the dashboard. It is a way of thinking — a method that helps identify the causes of inefficiency. It is also a powerful tool for identifying and eliminating hidden losses in production, allowing you to optimize processes without additional investment. With OEE, you can:
• Identify where time is being lost
• Determine which type of loss is most critical
• Start improving with minimal resources
By identifying losses in availability, productivity, and quality, you can significantly increase efficiency.
Want to know what is really slowing down your production? Use OEE — and let your data provide the answers.
Implementing the BEEDIGIT solution automates analysis and reduces the time spent identifying problems, allowing you to quickly solve problems and increase productivity without significant costs.
