Comparison of standard normal distribution (with mean = 0 and standard deviation = 1, coloured green) and the distribution shifted by 1.5 sigma (with mean = -1.5 coloured blue, and mean = 1.5 coloured red) on the effect on the upper and lower specification limits (USL and LSL, respectively).
<a href="//commons.wikimedia.org/wiki/User:Cmglee" title="User:Cmglee">Cmglee</a>
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>