What is difference between Firm and Non-Firm work orders?

Hello everyone,

I am not totally clear on the difference between Firm and Non-Form work orders.

The documentation says that work orders with the Firm box check ON  will prevent the automatic scheduling from changing the work order and wo operation palnned dates. It makes some reference to the EAM planning process and to MRP but does not get into details.

I would appreciate if someone could elaborate on the details please. And, in the case where a work order is not firm, what triggers an automatic reschedling. If material plays a role in this then, exactly how?

Thanks and regards,