There can be requirements like show shipments based on some complex query criteria(which cannot be written using simple default query criteria provided in screen sets) and also show related order releases for selected shipment in same screen, etc.

In such requirements we can use advanced layout which gives option to split the screen into panels and each panel can be associated to different business objects(like Order Release, Shipment, etc). We can have parent, child relationship between panel data(like shipment to order release). We can also associate saved query(SQL) to display results while launching the screen using these advanced layouts.