How to measure the average wait time in checkout lines of a grocery store
1) Assign a job duty of wait time measurement to a person (let’s call him or her a ‘roaming manager’) and let him/her carry a barcode scanner with a keypad. When a roaming manager finds a new customer arrive in a check out line, then the roaming manager scans one of the product of the customer and enter the cashier line number through the keypad of portable scanner. Then datawarehouse can calculate the wait time from the difference between the roaming managers scan and actual cashier scan.
Pros: very simple implementation with almost no cost, no interruption to customers. Cons: Customer could change the line after roaming manager scanned. But the errors will spread out and the average will still have a good use.
2) Make and distribute special barcode printed in plastic cards (maybe the size of a credit card or bigger). This card includes identification number and special code about the purpose (wait time measurement). When a customer approaches to the end of line, the roaming manager scans one of these cards (he/she should carry a lot of such cards) and hand it to customer or put it into customers shopping cart. Then the cashier scans this “fake” product just to measure the wait time.
Pros: Simple and low cost implementation. Customer can change the line without affecting data. Cons: We have to explain our intention to the customers. Maybe we could give the customers a little bit of incentive proportional to the wait time. For example, like 5 cents per minute of wait time.
3) Attach RFID card to every (or some of them just for sampling) shopping cart (and small carrier too) and install RFID reader station near to the usual end point of waiting line and the exit point. When a customer approach to the end of waiting line, RFID reader will read the time and ID of the shopping cart. Another RFID reader at the exit point will scan the end time of payment. If we install RFID reader station to several critical places in the floor (eg: Entry, Pharmacy, Grocery, Dairy Products, etc.), the datawarehouse may be able to use those movement data to calculate the typical behavioural patterns of customers and will benefit to display our goods in more efficient way. The experts in this area may find other good use of the movement data.
Pros:All automatic. No need for roaming manager. Cons: Initial implementation costs. Too much data inflow to datawarehouse.