I was assigned to work on a shopping cart for an online clothing retailer. By the time this client approached us, it was just a few days before Christmas, and their shopping cart had a big problem.
Say for example that you added a blue polka dot shirt of size “large” to your shopping cart. Then, after continued browsing through the online catalog, you decide that you want a “small” blue polka dot shirt. The problem was that after adding this shirt of size “small”, your shopping cart would contain two (correct) shirts of size small (wrong). Obviously, you should have a small shirt and a large shirt.
