A method includes performing a semiconductor fabrication process on a plurality of substrates. The plurality of substrates are divided into a first subset and a second subset. A rework process is performed on the second subset of the plurality of substrates but not on the first subset. A respective mean value of at least one exposure parameter for a lithography process is computed for each respective one of the first and second subsets of the plurality of substrates. A scanner overlay correction and a mean correction are applied to expose a second plurality of substrates on which the rework process has been performed. The mean correction is based on the computed mean values.