Digital service platforms are the facilitators of value co-creation within service ecosystems. They are instrumental in the design of compelling value propositions.Despite the substantial amount of contributions for the conceptualization of digital service platforms, the methodological contributions concerning the engineering of service platforms are scarce. In this paper, we adopt a service systems perspective and present a methodfor the identification of digital service platform requirements. The methodis driven by the value propositions that are based on the capabilities of the actors in service exchange networks. In the paper, we demonstrate the methodby applying it to an international Mobility-as-a-Service platform development project.