Here is a statistical table displaying the recommended minimum process capability for two-sided and one-sided specifications as against existing processes, new processes, etc. Use this Recommended Minimum Process Capability Table to plan your process improvement plans. Process capability index or ratio express more capability with the increasing higher values. It is the ability of the process to produce desired output within a specified time period and limits.
| Situation | Recommended minimum process capability for two-sided specifications | Recommended minimum process capability for one-sided specification |
|---|---|---|
| Existing process | 1.33 | 1.25 |
| New process | 1.50 | 1.45 |
| Safety or critical parameter for existing process | 1.50 | 1.45 |
| Safety or critical parameter for new process | 1.67 | 1.60 |
| Quality Process | 2.00 | 2.00 |
Since the process capability is a function of the specification, the recommended minimum process capability index is good as for both the two-sided and one-sided specifications. Both the specification values ranges from 1 to 2.
