When a scenario is created or modified in the ACC, its definition is saved in the scenario registry (located at the Nucleus path /atg/registry/data/scenarios) as a file with the extension .sdl. Scenarios are defined using the XML-based Process Definition Language. The Process Definition Language DTD (pdl.dtd) describes the formal syntax of the language. (The PDL DTD is located in <ATG10dir>\DSS\lib\classes.jar. For an example of a scenario definition file, look at one of the .sdl files in your scenario registry.) The scenario server reads the .sdl files from the registry and parses them into scenario objects.

After the scenario is parsed, each segment of the scenario is converted into an SSM.