Instructions

Complete the following exercises from the textbook "Software Engineering $10$th Edition" by Ian Sommerville found on page $122$:

Exercises $4\mathrm{.}1,4\mathrm{.}2,4\mathrm{.}3,4\mathrm{.}5$ and $4\mathrm{.}8$

The text for each of the exercises noted above is also included below for your convenience:

$4\mathrm{.}1.$ Identify and briefly describe $4$ types of requirements that may be defined for a computer$-$based system.

$4\mathrm{.}2.$ Discover ambiguities or omissions in the following statement of the requirements for a part of a ticket$-$issuing system:

An automated ticket machine sells rail tickets. Users select their destination and input a credit card and a personal identification number. The rail ticket is issued, and their credit card account charged. When the user presses the start button, a menu display of potential destinations is activated, along with a message to the user to select a destination and the type of ticket required. Once a destination has been selected, the ticket price is displayed, and customers are asked to input their credit card. Its validity is checked, and the user is then asked to input his or her personal identifier $($PIN$).$ When the credit transaction has been validated, the ticket is issued.

$4\mathrm{.}3.$ Rewrite the above description using the structured approach described in this module. Resolve the identified ambiguities in a way that could be implemented and then verified.

$4\mathrm{.}5.$ Using the techniques suggested in this module, where natural language descriptions are presented in a standard format, write plausible user requirements for the following functions.

An unattended petroleum $($gas$)$ pump system that includes a credit card reader. The customer swipes the card through the reader, then specifies the amount of fuel required. The fuel is delivered, and the customer's account is debited.

The cash$-$dispensing function in a bank ATM.

In an internet banking system, a facility that allows customers to transfer funds from one account held with the bank to another account with the same bank.

$4\mathrm{.}8.$ Who should be involved in a Requirements review? Draw a process model diagram showing how a requirements review might be organized.