COSMA proposes a novel SLA management approach for composite services. It supports a composite service provider in managing SLAs with providers of atomic services, in managing SLAs with requesters of composite services, and aligning both SLA management activities with each other. On this basis, a composite service provider can control and optimize its composite SLA management activities during the entire SLA lifecycle. This includes, in particular, planning and negotiating SLAs, monitoring and evaluating SLAs. In this paper, a case study on managing SLAs in composite services with the COSMA approach is presented in detail.