This application can compute the ARL (Average Run Length) of a Xbar control with variable sample size (VSS).

In addition, it performs an optimization of the parameters (warning limit, control limits and the two sample sizes) in order to minimize the out-of-control ARL.

It makes an ARL curve to compare the performance of the standard Xbar chart and the Xbar with VSS.

At the moment the supported languages are Spanish and English.

There is a twin Windows app with the same features that can be downloaded here:

https://mega.nz/#!vcxVSSrb!5axHvyzwJk8RQtcK2wXvUB5f70GaxiGXCDajSMxhKBU

This application is also available for iOS (Iphone, iPad) and OS X (MAC). Just search in their stores.