Manufacturing companies face the challenge due to more global and competitive markets to meet the individualisation mega-trend. They realise this by various offered product variants to provide the customer a high product variety. As a result an increasing complexity in the companies, such as rising costs, increased delivery times and higher error rates are implicated. Using modularisation the development of modular product structures avoids this variant induced complexity, so that high customer (external) product variety with simultaneous lower internal variety can be offered.In the DFG project WiMo " Development of a model describing the characteristics and effects of modular product structures to assess methodological approaches” a basic theoretical model was developed for the description of properties and specific determination of the impact of modular product structures in so-called effect chains in which existing part models from the literature have been integrated and merged. The previously existing knowledge gap was especially considered in relation to the specific investigation of the impact of modular product structures. Complementing existing case studies from our own research projects as well as the literature were analysed and integrated into the impact model.The resulting impact model will be validated in the transfer project with Siemens, in particular with Siemens Consulting, but also at the same time further detailed and extended. Siemens Consulting brings its own industrial experience of modularisation projects for over 10 years and is therefore an ideal partner for this transfer project. The validation shall be made on three modularisation projects carried out from different business areas from Siemens. In particular the objective of quantifying the effect chain is from great interest for the industry partner, because a forecast of the targets of cost, time and quality should be possible. In addition, it should be possible to make statements to the occurrence of certain effects through the extension of a temporal dimension at the impact model. Still it should be possible that a detailing of exemplary effect chains can quantitatively measure the impact, which only can be tested and evaluated with an industrial partner. For a better management of the extended and more detailed impact model it should be represented in a MBSE tool, to analyse the quantification in a better way.