Methods and systems for determining reticle deformations

Disclosed herein is a computer system configured to use a reticle heating model to determine the shape and/or deformation of a reticle and control the operation of a lithographic process that uses the reticle in dependence on the modelled shape and/or deformation. The computer system is configured to determine, in dependence on generated reticle process data and known thermal properties of the reticle, that a long track hiccup has occurred and in response to determining that a long track hiccup has occurred, reconfigure the reticle heating model to the same state initialized states used at the start of performing lithographic processes on the lot of substrates.