testing

[sunitha]

can anyone tell me wat is process capability ratio and expalin it ?

[bizzzzzare]

Hi Sunitha,

Process capability ratio describes what portion of the specification is a specified process taking up. It is indicated by cr.

Incase cr is greater than 75%, we consider the process as capable.

The process capability ratio is a process improvement method where we calculate the ability of a process to produce output within the specification limits. For calculating the cr, we calculate a few other dependent factors as well like :
1) USL - upper specification limit.
2) LSL - lower specification limit.
3) Estimated standard deviation of process.

Cr = usl - lsl / 6 * estimated standard deviation.

We could measure against specifications like strength, concentration etc. We genreally compare Cr values against recommended values. We measure it for existing as well as new process.

Cheers.....