In order to maintain their competitiveness and to respond effectively to different customer needs, manufacturing companies offer a wide range of product variants. This increasing product variety leads to an increase in variety-induced complexity and thus to rising costs in all departments. The development of modular product families is a proven strategy to handle the large external variety with a relatively small internal variety. Modularization requires not only technical-functional, but also organizational, process-related and strategic aspects from all involved departments in order to create an optimal product architecture. The method of the Life Phases Modularization offers this possibility as it integrates all perspectives of the different departments and tries to harmonize the partially contradictory aspects using the Module Process Chart (MPC). The resulting harmonized module process forms the global optimum for exploiting potentials of modular product families within the entire company. The method was developed almost a decade ago and has been applied and refined over time in several industrial cases. This paper presents the method on the basis of two industrial examples and shows deficits and improvements in a consolidated manner.