I imagine it is the same in 7.x as with 6.x–with the IS Administrator, you can’t. The UI doesn’t provide for user inputs.
But you can using the built-in services. Refer to the built-in services reference for details. The key is once the task is scheduled, never change it using IS Administrator or your inputs will be lost. You probably want to code the service so that it either assumes a good default input value or does nothing at all if no input is present.
#Flow-and-Java-services#webMethods#Integration-Server-and-ESB