A useful tool to easily check the performance of your system once you have introduced your initial tolerances is the Quick Sensitivity tool. It is similar to the Tolerancing tool; however, in order to give fast results, it uses the Paraxial Focus compensation (where the back focus is the only compensator) and does not run Monte Carlo analyses. The output will show you the sensitivity of all of your tolerancing operands, in addition to listing the “Worst Offenders”, the top tolerances that are giving the largest degradation in performance. You can also see the estimated overall change in performance, as well as how much the back focused was changed while being used as a compensator. Because tolerancing can be such a time-consuming process, using the Quick Sensitivity tool is very helpful for getting a sense of how your system performs before you do a full tolerancing run.