Situation 2
Step-by-step guide situation 2 — Scanning and paying
Closing the ‘privacy gate’ after starting the CPS system serves two purposes. First, it protects the privacy of the customer going through the payment procedure, preventing an impatient customer from bumping a trolley into someone's legs. It also prevents an open connection with the store every time the ‘security gate’ is opened.
Payment at the self-checkout starts with a press on the ‘I want to pay’ button. The camera checks whether there are products in the trolley, while the RFID reader reads the RFID codes on the products and builds an RFID shopping list from them.
Following the CPS system's instructions, the customer starts scanning the products. At each scan, the system checks whether the product appears in the RFID shopping list. The CPS system also checks whether the QR code of the scanned product matches the unique code in the supermarket's inventory database.
If the latter is not the case, the CPS system asks the customer to put this product back in the trolley and keep it separate from the other products. It may then be assumed that this is a product the customer already owned when entering the store. At the same time, the CPS system removes this product from the RFID shopping list.
If, when scanning a product, the CPS system establishes that the product does not appear on the RFID shopping list, security is alerted immediately. They check whether the RFID code on the packaging of the product concerned may be damaged. Security can correct for this.
Once the CPS system has established that the QR code of the scanned product appears in the inventory database, the data is stored in the QR shopping list and the RFID tag decoder is activated automatically; it is unnecessary, and too time-consuming, to have the customer confirm this QR code check. When the RFID tag decoder has done its work, the CPS system indicates that the next product may be scanned. The customer places the scanned product on the belt and picks up the next one, and so on. When the last product has been scanned, the customer indicates this by pressing the ‘end of scan’ button. Payment can then be made with the payment method of choice.
If the customer places a product on the conveyor belt without scanning its QR code, the CPS system detects a passing product whose RFID tag has not been deactivated. The belt is stopped immediately and an error message appears on the checkout screen asking the customer to scan the product again. If this succeeds, checkout can be completed. If not, security follows up with an appropriate anti-theft measure.
If, after the ‘end of scan’ button is pressed, the camera establishes that no products remain visible in the trolley or basket, but the RFID shopping list indicates products still to be paid for, security is called in. They check whether these products are perhaps in the customer's bag, asking whether the customer intends to pay for them after all. If yes, the process continues with point 3 of situation 2. If no, intended fraud may be at play. This can be confirmed by comparing the QR code on the packaging of the products concerned, via the QR reader, with the unique product code in the inventory database. Security then takes an appropriate anti-theft measure.
If, after the ‘end of scan’ button is pressed, the camera establishes that products remain in the trolley or basket which do not appear in the RFID shopping list, these are products whose RFID codes were deliberately damaged and, given the earlier check, not scanned. Security follows up with an appropriate anti-theft measure.
Once the scanning process has started, it can only be cancelled in one way. There are several reasons for this: a group of schoolkids may decide they don't want to send each other a payment request after all, a customer may decide on second thought not to buy certain products, or it may be a self-checkout where, say, a maximum of five products may be presented. The customer can then end the transaction by pressing the ‘return products’ button and continue as described in point 3 of situation 1.