Library Book Tracking System: This system is going to be capable of changing book status in the library with the help of library personnel with an information system. It will be available for users on the web only. The needs of customer who wants to use the system are listed as follows: Status of each book in the library will be shared with users. Users will be able to book requested literary work (books) for the next time if it is seized by another user. If a book is available right now, users will be able to book their requests. Users can extend release time. Keeping the dates of reservation and sorts users based on their booking request dates. Sending e-mail to the users for upcoming release times. Library personnel can update the status of books when users bring them back to the library. Generate debt accumulation info for unreleased books when permitted time interval violated by users, and send information to users. 1. Write down related requirements for given needs. The system shall provide shelf information and placement scheme for each book in the library. The system shall collect reservation information about each book. The system shall show reservation information about each book to users and library staff. The system shall show the current status (reserved/taken/available) of each book. The system shall support users to request a book. The system shall record users' requests chronologically (first request first take). The system shall update book status as requests are received within 5 sec. Users shall be able to reserve a book for the upcoming available status if it is reserved or taken by other users. System shall inform users about their remaining time weekly if the remaining time is greater than one week. System shall inform users about their remaining time daily if the remaining time is less than or equal to 7 days. System shall support library staff while updating the book status. System shall calculate delay time by considering releasing date information of the books. System shall inform the user about delay time and debt account (penalty charge) daily./ System shall inform users about unreleased books. System shall inform users about penalty cost value daily. The system should support users to extend the loan period if the user wants it. System shall record previous activities for 3 years (archiving-NFR). System shall inform the library staff about the users who do not release the reserved book(s). System shall support and update information for all communication tools that are available for library users and staff. System shall respond to user requests less than 10 seconds (NFR). Only library staff (NFR-access) shall see and update user information (FR). The system shall update debt information with a related library account. The system shall protect all credentials of users. 2. Develop the functional hierarchy for this system. FO- Provide a library tracking system book. F1. Provide book information. F1.1 Provide available book information. F1.2 Provide taken book information F1.3 Provide reserved book information F2. Provide reservation, book gathering and postpone the release date of the F2.1 Provide reservation for available books F2.2 Provide reservation for taken books F2.3 Provide taken books from library F2.4 Provide postpone chance the release date of a taken book. F2.5 Provide information about upcoming release dates F2.6 Provide information about penalty costs F3. Maintain the system and the service F3.1 Provide updates F3.2 Provide maintenance by IT personnel F3.3 Reduce average waiting time F3.4 Reduce mean time to repair F4 Control the system and its components F4.1 Support security system F4.2 Support and control back-up system F4.3 Support and control database