Abstract: The invention relates to a chromatography method of producing a target elution volume comprising a first and a second target protein. The method includes providing a cation exchange chromatography column; applying a protein solution on the column, the protein solution comprising the first target protein, a second target protein and optionally one or more further proteins; inputting an optimization criterion; computing chromatography simulations for computing an elution buffer salt concentration adapted to provide a target elution volume matching the optimization criterion best; computing the pooling borders of the target elution volume as a function of at least the computed salt concentration and the input optimization criterion; applying an elution buffer having the computed salt concentration on the chromatography column; performing the elution; and collecting the computed target elution volume.