Process Capability Evaluation and Analysis for Product Quality Management

Process capability indices (PCIs) have been widely used to evaluate and determine whether the manufacturing process meets the preset target of the customer in manufacturing industries. A larger PCI value means a higher quality yield. This study applies two PCIs, the accuracy index δ and the precision index γ, to analyze, improve and manage the process performance of a product. To address statistical sampling error, the (1 )×100% upper confidence intervals (UCLs) of δ and γ are derived. An example is given to illustrate the use of the proposed method, and is proven to give good results for practical applications.