With the uprising discussion around digitization, the value of product data has reached a new level. Product Lifecycle Management aims to play a core role in enabling the digital transformation in industry. The focus of PLM has traditionally been on the management of processes and data to define product types while many concepts of digitization rest upon individual product instances. In the context of current PLM implementations, this new perspective is not yet widely understood. A model that explains the interaction of product type and its instances along the business processes is missing. This essay suggests a PLM reference model that separates the lifecycles of product types and product instance. Four phases in a closed loop process explain the interaction between type and instance and how they are connected to the business processes of a company. The model results from a series of workshops with industrial experts and was applied in several industrial projects.