25. Draw a physical level 0 DFD for the following sys¬

tem and compare it to the logical model that you cre¬

ated in Chapter 6. A Video Store (AVS) runs a series offairly standard video stores. Before a video can be put on the shelf, it must be catalogued and entered into the video database. To rent a video, every cus¬

tomer must have a valid AVS customer card. Cus¬

tomers rent videos for three days at a time. Every time a customer rents a video, the system must ensure that he or she does not have any overdue videos. If so, the overdue videos must be returned and the customer must pay a fine before renting more videos. Likewise, ifthe customer has returned Books by Author overdue videos but has not paid the fine, the fine must be paid before new videos can be rented. Every morning, the store manager prints a report that lists overdue videos; if a video is two or more days over¬

due, the manager calls the customer to remind him or her to return the video. If a video is returned in damaged condition, the manager removes it from the video database and sometimes charges the customer.