Performance loss
This is a feature in RS Production OEE
In OEE, performance loss represents the time when the machine is running, but is not running at the optimum speed.
Simple calculation example
Optimum speed = 60 units per hour. This is the expected produced amount when everything runs perfect.
Produced amount = 60 units
Performance = produced amount / optimum amount
Performance = 60 / 60 = 100%
Produced amount = 30 units
Performance = produced amount / optimum amount
Performance = 30 / 60 = 50%
🤓 Note that Optimum speed sometimes is called “design speed” or “name plate speed”.
Based on running time only
Downtime (red time) is not included in the performance calculation. Only the uptime/running time is included.
Clock time = 60 minutes
Uptime = 40 minutes
Optimal cycle time = 60 s → Optimum amount = 60 units /h
Optimum amount = 40 units
🤓 Note that “Plannable speed” and “Effective time per unit” includes efficiency losses, and is different from optimum cycle time
Produced amount in different production processes
Of course, produced amount is differently expressed in different factories
Units per hour | Units per minute | Cycle time |
|---|---|---|
Products/hour, Kg/h, Meters/h | Products/min, Kg/min, Meters/min | Seconds/product, Seconds/meter, Seconds/… |
3600, 1000, 20 | 60, 16.67, 0.33 | 1 s, 3.6s, 180s (3 min) |
Products has different Optimum speed
Different products (articles) can have different optimal cycle time
Article/product | Optimal cycle time | |
|---|---|---|
Potato chips - 100g bags, Line A | 1,8 seconds | 2 000 bags per hour |
Potato chips - 250g bags, Line A | 3,0 seconds | 1 200 bags per hour |
Also, the same product can have different optimum cycle time in different machines (measure points)
Article/product | Optimal cycle time | |
|---|---|---|
Potato chips - 100g bags, Line A | 1,8 seconds | 2 000 bags per hour |
Potato chips - 100g bags, Line B (new) | 1,2 seconds | 3 000 bags per hour |
Example
As mentioned above, downtime (red time) is not included in the performance calculation.
Clock time = 1h + 1h = 2h
Uptime = 0,75h + 0,5h = 1,25h
100g Pepper chips | 225g Pepper chips | |
|---|---|---|
Optimal cycle time | 1,8 sec per bag | 3 sec per bag |
Optimum amount | 2 000 bags per hour | 1 200 bags per hour |
Optimum amount = (0,75h x 2000) + (0,5h x 1200) = 1500 + 600 = 2 100 bags
Produced amount = 500 + 500 = 1 000 bags
Performance = produced amount / optimum amount
Performance = 1 000 / 2 100 = 47,6%