Z Schema: Library System

This presentation provides an introduction to the Z schema notation and its use in modeling computer systems, specifically the library system. It explains the background of the library system, the different Z schemas used, and the main functionalities of the system. It also discusses the consistency of the Z schema with the library system and the predicates associated with it. The presentation concludes by highlighting the benefits of using the Z schema and its ability to improve and upgrade the system.

Software Testing
Z SCHEMA: LIBRARY SYSTEM

Introduction
 The Z notation also known as the Z
schema is a formal specification language
that is mainly used for modelling computer
systems and describing them. This
notation is targeted toward the clear
specification of computer based system in
general and computer programs.
 The Z schema is designed based on the
standard mathematical notation that is
used in the axiomatic set theory, first
order predicate logic and lambda calculus.
 The expressions in the Z notation are
typed.

background of library system
 The library system is a system that
can be used to perform the functions
of the library. Some of the core
functions of this library include:
 1. Adding a book
 2. Delete a book
 3. Add a borrower
 4. Return a borrowed book
 5. Reserve a book.

background of library system
(continued)
 6. Cancel a reservation
 7. Receive a book
 8. Buy a book
 9. Enquire for a book
 10. Delete a borrower
 11. Lend a book
 12. Report loaned books

z schemas
 The Z schema notations for the library system can be divided into two
three parts. These parts are:
 1. User defined types:
 [BORROWERID,RESERVATIONID,PHONE_NUM,LENDID,BOOKID,DATE]
 2. Free types:
 STATUS ::= AVAILABLE | SOLD | WAITING | CANCELLED | LEND
 REPORT::= SUCCESS | BOOK_NOT_KNOWN | BORROWER_NOT_KNOWN
| BORROWER_ALREADY_KNOWN | BOOK_NOT_KNOWN

z schemas (continued)
 3. Start spaces
 A. Book
 B. Borrower
 C. Lend
 D. Reservation

z schemas (continued)
 4. Error handling
 A. Success
 B. Already_known_book
 C. Already_known_borrower
 D. Not_Known_Book
 E. Not_Known_Borrower
 F. Book_Not_Available

Functionality
 The main functionalities of the
system are:
 1. Add a book
 2. Add a borrower
 3. Delete a book
 4. Delete a borrower
 5. Lend a book to a borrower

Functionality (continued)
 6. Return a book from a borrower
 7. Enquire about a book
 8. Reserve a book
 9. Enquire about a reservation
 10. Cancel a reservation
 11. Buy a Book
 12. Report of Books on Loan

Consistency with the library
system
 The library system developed
using the Z schema has all the
functions of a normal library. A
normal library has functions like
lend a book, retrieve a book,
record borrower, add borrower,
delete borrower, etc.

Predicates
 The predicates of the library system are:
 1. lends, borrower(x)
 When you book that is lend there is always a borrower. This statement is
always true.
 2. lend, book(x)
 For every person who is lend a book, there is always a book. This statement is
also true.
 3. lend, borrowDate(x)
 For every book lend, there is always a borrower date. This statement is again
true.

Conclusion
 To conclude, the Z schema is a system or a set
of notations to demonstrate the functioning of
a system be it a library management system or
a ticket booking system. The normal tasks
carried out in the system is implemented
electronically via expressions in a Z schema.
 It provides the users with the ability to make
changes or improve the system by making
changes in the notations and upgrading the
system as per requirement.
 The library management system in this report
has been completely denoted via the Z schema
and its tasks are clearly shown with the help of
expressions.

References
 Spivey, J. M., & Abrial, J. R. (1992). The Z
notation (p. 90). Hemel Hempstead:
Prentice Hall.
 Singh, M., Sharma, A. K., & Saxena, R.
(2016). Formal Transformation of UML
Diagram: Use Case, Class, Sequence
Diagram with Z Notation for Representing
the Static and Dynamic Perspectives of
System. In Proceedings of International
Conference on ICT for Sustainable
Development(pp. 25-38). Springer,
Singapore.

THANK
YOU