The European automotive industry can be characterized by its multi-variant products resulting in complex production planning problems. Often separate systems are used to plan personnel capacity and production programmes. Usually human-resource allocation planning is done very inefficiently and independently from actual capacity requirements. This causes imbalances in the form of idle workers or overloaded workstations. This paper describes an approach for the integration of human resource allocation and production planning into one common planning platform in order to utilise existing optimisation potential. It will further describe the impact of the solution on flexibility and mutability of assembly lines.