Nowadays, service compositions are increasingly used to execute business processes. During the execution of a service composition, a service failure leads to a necessary re-planning. Due to such runtime events, the ex-post realized Quality of Service (QoS) values and thus the realized utility of an executed service composition may be significantly lower than the ex-ante computed one. The presented paper examines how the consideration of the effects of potential service failures can be modeled for an ex-ante QoS-aware service selection using expected utilities. Furthermore, we analytically evaluate our approach and demonstrate its applicability by an example. By doing so, we show that considering the effects of potential service failures leads to substantial better decisions about the QoS-aware service selection.