In recent years, companies have been struggling to best cope with the increasing request for customized and personalized products that characterizes mass customization paradigm. The efficient management of product variety requires effective solutions to make companies able to deliver such products in a short time and at a high-quality rate. The Delayed Product Differentiation (DPD) is rising as one of the most effective strategies to manage mass customization, implemented in practice using product platforms. Platforms are intermediate products formed by the most common components within a product family and managed through a make-to-stock strategy. After the arrival of the customer order, platforms are transformed into the final variants through assembly/disassembly customization tasks, delaying the final product differentiation point. In such a scenario, this paper proposes an innovative decisional algorithm for product platform design and selection to reduce the overall effort for platform customization into final variants. The application of the procedure to a reference industrial case study showcases its relevance and validity in managing high product variety.