Divergent customer requirements demand a product portfolio, which needs to be strategically coordinated. Furthermore, products are developed in generations. Thus, a coordination of the different generations is needed. For a successful support, process models can be used. The integrated-Product-engineering-Model (iPeM) is an integrated approach, which aims to fill in the gap between process management and engineering design. Building on an empirical study of the use of the iPeM in the last 10 years, the iPeM has been modified. This includes an adaption of the activities and an extension from the second to the third dimension. There are four different layers added: product generations, strategy as well as production- and validation system. The adapted model allows inductively refining the theory and deductively creating of boundary conditions for the research on product development.