I have to have a GUI that an operator can enter data in to start a test. Once the test is running the GUI displays the status of the test. Most test take several hours. The user can not stay logged in and other users need to be able to log in and see the progress of the test. My first thought was a service but I can't have a GUI in a service. What is the best way to tie the GUI to the Service or at the very least have the service pump data to the GUI?