Customer railway system construction during Tendering is challenged by numerous factors: the heterogeneity of customer background (diversity of culture, context, preferences etc.), the complexity of the system to construct and the coordination of several teams with expertise on diverse areas of system development which need to share a common understanding and coherence of the system to deliver.In this paper we show how semantics can contribute to the knowledge management and thus the improvement of the Tendering process. A first study carried out in the company led us to the conclusion that ontologies are a suitable means to overcome the shortcomings that appear during this process and we explain through a model and a first implementation how this can be achieved.