In this study, the process capability index (PCI) was used to investigate the process level of smartphone hand tool K produced by company M in central Taiwan. The smartphone hand tool K has three key quality characteristics, namely, full length, front handle length, and dot width. The result of this study shows that, by using process capability index Cpk, the "dot width" is an unqualified quality characteristic, which should be as the primary improvement for company M. The result of this study can effectively improve the smartphone proprietary hand tools process level for company M, and to be a reference for the implementation of relevant industry process improvement.
