Not when your Xmas shopping has half the items missing it isn't. Happened to a friend of mine today - she is currently driving around Oxfordshire trying to find a Turkey :)
That is the self service checkouts. Self scanning is you scan every item with a handset as you put in your bag in the trolley. Once done, you scan a barcode on the self service checkout which transfers everything to the checkout, you pay and bosh, done. Your shopping is already packed and...
The keys to Xmas shopping in Supermarkets are:
Have a list and know where everything is before you go in. Plan your route and do not deviate from it.
Go in pairs with one trolley so that one can whizz down aisles without the trolley whilst the other waits at the aisle end, grab what you want...