Statistical Analysis and Improvement of Process Capability Indices

To increase product quality and predict the unqualified products, effective control methods must be selected. Considering the disadvantages of process capability indices C_p and C_pk that are hard to help to find the reason of quality problems and direct quality improvement, three new indices C_ps, C_pc, and C_pc available in real time are introduced to control the scatters and errors. Finally the feasibility of these indices is proved by an application.