Abstract: This paper presents an approach for detecting and resolving feature interactions (FI) in telephone systems. In this approach, the basic telephone system (POTS) and the features are each represented as a temporal colored Petri net (TCP-net). When the POTS is enhanced with some features, their TCP-nets are integrated. The functionality of a feature is represented as a temporal formula and the behavior of the enhanced system is represented as the set of all firing sequences each of which realizes a transition-invariant of the TCP-net representing the feature. FI can be detected by inspecting whether or not the temporal formula is violated when executing some of these firing sequences. Three theorems are provided for finding realizing sequences and detecting FIs. Detailed examples are used to illustrate the specification of telephone features and the detection and resolution of FIs.