You will need to call WMS APIs in EBS from SES. There are multiple options available ranging from simple to complex and it also depends on what dispatcher you are using. The simplest option is to call WMS APIs using event flow dispatcher. You need to specify the WMS data source in data-sources.xml and specify which API gets called under what circumstances in event flow XML. For more complex needs you could potentially use other dispatchers such as streams dispatcher and use other fusion middleware components such as BPEL, BRM, etc to call WMS APIs.