This paper reports on the main results from an industrial cooperation project¹. The project is a joint project between Nokia Research Centre and the CPN group at the University of Aarhus. The purpose of the project was to investigate features and feature interactions in development of Nokia mobile phones through construction of a Coloured Petri Nets (CPN) model. The model is extended with domain-specific graphics and Message Sequence Charts to enable mobile phone user interface designers and software developers who are not familiar with Petri Nets to work with the model. The paper presents the CPN model constructed in the project, describes how domain-specific graphics and Message Sequence Charts are used in simulations of the CPN model, and discusses how the project and in particular the construction of the CPN model has influenced the development process of features in Nokia mobile phones.