Do these stories one by one.

1. Save a customer into a collection.
2. Make sure you can couple a loyalty card with a customer. This contains a barcode and bonus points.
3. Make sure you can find you customer by a loyalty card barcode.
4. Make sure you can save the groceries by day.
5. Make sure you can search for the item that a specific customer bought the most.
6. Make sure you can search for the items that a specific customer bought only once.
7. Make sure you can guess the items a customer is going to buy based on the day of the week. For instance 9/10 times they bought a fish on friday.
8. Make sure you can export a report on amount bought per item. This should be a report for each customer and not for just a single customer.
9. Search for customers that haven't shoped within a year.
10. When you add groceries to a customer, a customer will receive a bonus point for each item they bought 2 consecutive times.
11. For each consecutive time a item get bought the amount of bonus points will double. For instance a customer bought bananas 4 times in a row, that customer will receive 8 bonus points.
12. Limit the previous item to 10 bonus points.
13. When a customer reached 50 bonus points a coupon for 5 euro will appear.
14. Bonus points have a limited lifetime of a year.