Complexity cost management refers to costs in industrial production processes that are directly or indirectly related to the handling, management or creation of different variants of a product. The current understanding and state of awareness of the influence of complexity on cost structures is reflected in the results of a survey carried out by the authors. The methodology used to analyse the complexity costs of existing processes is described and a case study from the automotive industry, which is highly affected by variant-driven complexity costs, is introduced. Furthermore, a model to calculate potential complexity costs, when changing product variety based on the number of variants, variant drivers and the characteristics of variant drivers, is shown. Finally, an easy-to-handle tool, which allows more detailed determination of complexity costs based on changing product variety parameters, is presented.