A New Capacity Evaluation Index for Process Statistical Steady State

After analysing applicable limitations of process capability index Cp and process performance index Pp, we put forward a new evaluation index, which can evaluate statistical stability in a production process, and identify abnormal influence factors. Based on probability and mathematical statistics basic theory, we analysed and proved application principle of the new index, and proved that the new index had objectivity in evaluation in theory. With grinding process sampling data, we verified the new index applicability. The new calculation is simple, and has quantitative criterion, the new index is useful in production site.