Software Engineering

Evaluate ambiguities or omissions in the following statement of requirements for part of an airport ticket-issuing systems: An online ticket-issuing system sells air tickets. Users select their destination and input a debit card and a personal identification number. The air ticket is issued and their debit card account charged. When the user presses the login button, a menu display of potential destinations is activated, along with a message to the user to select a destination. Once a destination has been selected, users are requested to input their debit card. Its validity is checked and the user is then requested to input a personal identifier. Once the credit transaction has been validated, the ticket is issued. Ambiguities and omissions include: a) Can a customer buy several tickets for the same destination together or must they be bought one at a time? b) Can customers cancel a request if a mistake has been made? c) How should the system respond if an invalid card is input? d) Must the user press the login button again if they wish to buy another ticket to a different destination