A capable process is determined to be when the

Standard deviation of the process only is operating such that its upper and lower control limits are acceptable relative to the upper and lower specification limits

$\frac{C_p}{C_{pk}}$ is less than $1\mathrm{.}0$

Mean of the process only is operating such that its upper and lower control limits are acceptable relative to the upper and lower specification limits

Mean and standard deviation of the process are operating such that the upper and lower control limits are acceptable relative to the upper and lower specification limits

What's happening $>$ what's acceptable