PEST is a general purpose parameter estimation utility developed by John Doherty of Watermark Computing. The PEST interface in GMS can be used to perform automated parameter estimation for MODFLOW. The steps involved in setting up a PEST run are described in the automated parameter estimation topic.
The PEST options are edited by selecting the Parameter Estimation command in the MODFLOW menu and then clicking on the PEST tab.
Related Links:
Automated Parameter Estimation