CP¶
Category: EGTools-only function
Process capability index Cp from measurements and spec limits.
Syntax¶
=CP(data, [usl], [lsl])
Arguments¶
| Argument | Required | Description |
|---|---|---|
| data | Required | measurement range or array |
| usl | Optional | upper spec limit (optional if LSL given) |
| lsl | Optional | lower spec limit (optional if USL given) |
Returns¶
Returns the process capability index Cp = (USL-LSL)/(6σ) as a scalar number. Missing data or both limits missing returns #VALUE!; fewer than 2 numeric values returns #NUM!; a zero standard deviation returns #DIV/0!.
Examples¶
| Formula | Result | Description |
|---|---|---|
=CP({1;2;3;4;5},6,0) |
0.632455532 | Cp for spec limits 0 to 6 |
Notes¶
- Uses the sample standard deviation (n-1).
- If only one limit is given, the missing side is treated as the mean.
- USL·LSL accept arrays and are computed element-wise, spilling an array of the same shape — scalars are broadcast, a column vector × a row vector expands to their outer product, size-mismatched elements yield #N/A, and an error element returns that error.
- Related function: CPK
- Supported: Excel 2010+. Always registered as
CPon every Excel version.