1. A computer-implemented method of a scenario execution environment having a plurality of action layers, the method comprising: in a processor: parsing scenario execution environment code having a scenario operative with a plurality of interfaces of a service, the scenario execution environment code specifying at least one scenario execution environment action for the scenario, the scenario execution environment action having a scenario execution environment variable specification; identifying at least one of the plurality of action layers associated with said at least one scenario execution environment action specified by the scenario execution environment code, the at least one of the plurality of action layers configured to interact with at least one of the plurality of interfaces by having the scenario execution environment action activate an element of the at least one of the plurality of interfaces of the service; replacing the scenario execution environment variable specification with a variable value retrieved from the at least one of the plurality of action layers; dispatching said at least one scenario execution environment action, as modified with the variable value, to said at least one of the plurality of action layers identified as being associated with said at least one scenario execution environment action; and processing an action result returned by said at least one of the plurality of action layers.