Many of our sites will set up a general Machine under each line to accommodate the situation. It is usually the same name as the line, that way work orders can be entered against the whole line not a specific machine within the line. You can also tag it as a non production machine that way it won't impact your reports or data. Many times the parent-child work order is used in this type of scenario where there is the same type of work occurring on multiple machines. This way you can track that all machines have been completed.
A machine is required to set up a Work Order because the Dispatch must be launched against a machine. When creating a Work Order you'll need to choose the Area and Line. You can set up a default machine for your line in Setup>Line>Default Machine.
What does 'Require Machine Selection' set to True vs. False mean?
When 'Require Machine Selection' is set to true, you will be given a drop down menu of machines tied to the Area > Line that you set up your Work Order for.
When 'Require Machine Selection' is set to False, it will automatically default to the Machine you have set up as your default for the specified line.