Service-oriented architecture (SOA) enables organizations to transform their existing IT infrastructure into a more flexible business process platform.. In this architecture, decoupled components that provide standard services can be composed to form individually configured and highly flexible applications. When building such applications it is important to have a formal specification of the interaction protocols between the composed services not only because such a specification provides an accurate and unambiguous description of the interactions and their ordering but also to enable automated verification and validation. In this paper, we present a case study from the SAP context showing the interactions between two SAP service components and use that case study to derive a set of modeling requirements. This motivates a discussion about applicable techniques for service choreography modeling and whether existing choreography languages cover the identified needs.