Consider the following software system designed for a video store: A Video Store (AVS) is a smallvideo store renting various kinds of videos. It has a manager, an accountant, and a technician responsible for maintaining AVS's computer hardware/software. Befor e a new video can be put on the shelf,its information must be entered into the database by the technician, including a video id, a video name, and a short description. Before renting a video, a customer must apply for the membership by providing his/her name, address, and phone number. After the application is done successfully, the customer is provided a customer card with a unique customer id so that he/she can rent a video from AVS. AVS has a website telling the information of each video, such as its id, name, content, and availability. The website will run 24 hours a day, 7 days a week. Most of customers are novice at the internet. If a customer wants to rent videos, he/she must physically go to the store in person. When renting vides in the store, a customer shows his/her card and tells the manager what video(s) he/she wants. Customers can only rent a video for three days at a time. The rental information of each video includes a rental id, customer's id, customer's name, customer's phone number, customer's overdue information, the date of the loan and the date of return. Every time a customer rents a video, the system must ensure that this customer does not have any overdue videos. If so, the overdue videos must be returned and an overdue fee must be paid before the customer can rent more videos. Every morning, the store manager prints a report that lists overdue videos and calls the customer to remind him or her to return the video. Every morning, the store manager also checks all videos returned the day before. If a video is returned in damaged condition, the manager removes its information from the database and may sometimes charge the customer