Much evidence identifies innovation as the main driver for companies to prosper, grow, and sustain a high profitability. New innovation models of so called ‘Open Innovation’ make companies rethink their innovation management, as it is assumed, that the implementation of such models result in better innovation performance. The relatively young field of research is expanding in many directions and the ongoing debates cover a multitude of areas connected through the overall aim of understanding how both high- and low-technology companies can become more innovative. Since the implementation of open innovation models depends among other factors on the industry sector, the model has to be adapted for each company. This paper reveals an overview on existing models on external as well as internal factors influencing companies’ innovation management and combines them to a new model on open innovation and its influencing factors. To point out the practical relevance of these influencing factors, we apply the open innovation model and its influencing factors on the case of the postal sector.