App note from ONSEMI about their high side SmartFETs and their specific application. Link here (PDF)
The “end requirement” from a high side SmartFET is to switch loads, and there are different alternatives, available in market, towards that end. Relays, for instance, have been used for long in the industry to switch various automotive loads, especially those requiring high current activation. With a continual reduction in the weight and size of automotive components and assemblies, there has been an evident transition from relays to semiconductor switches that take up less area and also offer improved noise immunity and lower electromagnetic interference as compared to relays.