The relationship between the process capability and the design specifications is measured by the ________.

A) process control index
B) process control monitor
C) process capability chart
D) process capability index

The process capability index (PCI) measures the ability of a process to consistently produce parts that meet design specifications. It takes into account both the process variability and the distance between the process mean and the specification limits. A value of 1 means the process is performing perfectly, while values less than 1 indicate that the process is producing parts outside of the design specifications. As such, the PCI is the best measure of the relationship between process capability and design specifications.