The increased demand for product variety has implied that many manufacturing companies are struggling with managing product complexity. This article suggests a framework for combined modeling of product variants and the process flow in production and assembly for customized products. The aim of the framework is to create a visual model that illustrates the product variety relative to the process flow and provides transparency of product variety in the different process steps. Literature has suggested various methods and techniques. These provide means for reducing complexity based on analysis of the end product, but do not pay much attention to understanding where in the production and assembly processes, this variance occurs. The suggested models form a basis for analyzing and reducing product complexity based on a visual model of the product variety in each process step. The models gave rise to a reduction of the SKUs with 33% without losing product variety offered to the end customer. The initial test of the framework and models in the case company showed that the models can provide new insight into the product variety, which forms a solid basis for making decisions on reducing product portfolio variety and adjusting the order decoupling point.