Due to benefits such as interoperability and reuse, there is growing adoption of SOA in organizations. The use of SOA and BPEL is a usual way to automate business processes. In a SOA with a high number of business processes sharing services, the analyses of the combined action of these processes on a particular service can be complex. These analyses are relevant, for example, when attempting to guarantee the performance of a service, or to visualize the fragmentation level of a SOA. This paper proposes a representation of business processes in a SOA in the form of a multidigraph, in order to facilitate analyses of the action of business processes in shared services.