You might want to create a service in this way to act as a wrapper for the called program. In this context, a wrapper refers to a logic part that has no meaningful logic in itself but that exists to give other applications access to another logic part.
To create a service to call a program:
If you type the name of an existing Service part and then select Update existing files, EGL adds a function to the existing Service part that calls the called program. If you type a name for a new Service part, EGL creates the new part and adds a function that calls the called program.