Scheduling additional trains is an essential task of railway systems. Under the pressure of increasing demand for railway networks, academia has worked in recent decades on the modeling and solving of this task. To be truthful to reality, models must consider the involved stakeholders and account for technical conditions. Satisfying these different interests leads to several objectives. However, extensive studies on objective relations are lacking in the literature, especially for more than four objectives, while practitioners need to deal with larger numbers. As a first step to fill this gap, we study the correlation between pairs of eight objectives of the Swiss Federal Railways.