Solution for Drawing Use Case Diagrams

Information Requirement Analysis Tutorial

Use Case Modelling Revisited Tutorial

Consider the following narrative:

        The Highbrow University library system manages the loans of all staff and students on the campus. All borrowers are issued with a library card which is swiped when the borrower presents it at the counter together with the books that he/she wants to borrow.  The library assistant will check that the potential borrower does not have any outstanding debts or overdue books before issuing any new books. The library assistant will then read the bar code of each book waiting to be borrowed and will stamp the book with the return date. The book and card will then be returned to the borrower.

When books are returned to the library, the borrower does not have to present his/her card. The librarian simply reads the bar code attached to the book and ‘books’ it back into the library. If there is a fine due on the book the borrower will be asked to clear the debt before borrowing any other books from the library.

All borrowers have access to the catalogue on an enquiry basis only. They may search for copies of a particular book stored at the campus library. Similarly, they may check their own status as a borrower - books currently on loan and debts accrued.

Now do the following:

a)        Construct a use case diagram for the Highbrow University library system outlined above.  

b)         Write primary scenario

c)         What questions may be asked to make clear

d)        Write secondary scenarios and a complete scenario

Sample solution:

Solution for question (a)

1. List all events

Action                                                Actor/receiver                                        

1.  Issue library card                                library assistant, borrower (staff, students)
2. Swipe card                                         library assistant
3. Borrow books        request                        borrower
4. Check validity                                        library assistant
5. Read barcode of books to borrow                library assistant
6. Stamp return date                                library assistant
7. Return card and books                        library assistant, borrower
8. Loan return                                        borrower
9. Read barcode of returned books                library assistant
10. Asked to clear fine                                library assistant, borrower
11. Access to the catalogue                        borrower
12. Search book copy                                borrower
13. Check own status                                borrower

1. Sort the List by sequence

1. Issue library card                                library assistant, borrower (staff, students)

k.        Access to the catalogue                        borrower

1. Search book copy                                borrower
2. Check own status                                borrower

1. Borrow books        request                        borrower

1. Swipe card                                         library assistant

1. Check validity                                        library assistant
2. Read barcode of books to borrow                library assistant
3. Stamp return date                                library assistant
4. Return card and books                        library assistant, borrower
5. Loan return                                        library assistant
6. Read barcode of returned books                library assistant
7. Asked to clear fine                                library assistant, borrower

1. group the List by event nature
2. give appropriate process name[pic 1]

[pic 2]

1. Issue library card                                library assistant, borrower (staff,

students)

[pic 3]

[pic 4]

k.        Access to the catalogue                        borrower

1. Search book copy                                borrower
2. Check own status                                borrower

1. Borrow books        request                        borrower

[pic 5]

[pic 6]

1. Swipe card                                         library assistant [pic 7]

1. Check validity                                        library assistant
2. Read barcode of books to borrow                library assistant
3. Stamp return date                                library assistant

[pic 8]

[pic 9]

1. Return card and books                        library assistant, borrower

[pic 10]

[pic 11]

1. Loan return                                        borrower

[pic 12]

1. Read barcode of returned books                library assistant
2. Asked to clear fine                                library assistant, borrower

(v). Draw use case , give title

Highbrow University library, loan control system

[pic 13]

[pic 14]

[pic 15]

1. Swipe card                                         library assistant

1. Check validity                                        library assistant
2. Read barcode of books to borrow                library assistant
3. Stamp return date                                library assistant

[pic 16][pic 17][pic 18][pic 19]

[pic 20]

Primary scenario

Pre condition        Borrower presented books to borrow with card and requested loan

1. Swipe card  
2. Check validity        
3. Read barcode of books to borrow
4. Stamp return date

Post condition        Return books and card to borrower

[pic 21]

To make clear we need to ask question like :

1. If card cannot be read barcode what will you do , to ask to Library assistance
2. If card is not valid for fines to pay what will you do , to ask to library assistance
3. If barcode of books to borrow cannot be read by the barcode reader what action will you take, to library assistance

Secondary scenario :

1. If card cannot be read then the barcode number under the barcode will be entered
2. If card is not valid for fines to pay then the borrower need to pay fine else exit
3. If barcode of books to borrow cannot be read by the barcode reader the barcode number under the barcode will be entered

Complete scenario