No, most of the time is wrong.
If you have a DeliveredOrder you want to make sure that is not delivered again, so the delivery function should accept only an Order, not a DeliveredOrder.
If in some different system you need a domain object that is both an Order and a DeliveredOrder than in F# you simply use an union type:
type Order = UndeliveredOrder of UndeliveredOrder | DeliveredOrder of DeliveredOrder
And in this way you can write a function that accepts both an UndeliveredOrder and a DeliveredOrder.
