Magnetic workholding has at least two significant advantages. One is that setups are fast. Clamping activates at the touch of a switch. This is true for a large part or for a series of parts machined in a single cycle.
The other advantage is that magnetic workholding involves no intrusive clamps. As a result, the machining center can reach five faces of the part in one clamping.
To better understand magnetic workholding, watch this short video produced by Earth-Chain. It shows how magnetic workholding is used with soft jaws for rapid and accurate part location. It also shows how magnetic workholding can still be used, even if the underside of the part is too warped to lie flat on the table.