In This Topic
PPM < LSL for Observed Performance
The number of parts out of one million that have measurements that are less than the lower specification limit is calculated as follows:
Notation
| Term | Description |
|---|---|
| LSL | Lower specification limit |
| N | Total number of observations |
PPM > USL for Observed Performance
The number of parts out of one million that have measurements that are greater than the upper specification limit is calculated as follows:
Notation
| Term | Description |
|---|---|
| USL | Upper specification limit |
| N | Total number of observations |
PPM Total for Observed Performance
The total number of parts out of a million that are outside the specification limits is calculated as follows:
Notation
| Term | Description |
|---|---|
| LSL | Lower specification limit |
| USL | Upper specification limit |
| N | Total number of observations |