Parking system changes

Requirements 1–5 are deleted.

New requirements:

9. The machine shall make it possible to print an unpaid ticket.

10. Each ticket shall have an unique ID number.

11. For each ticket, a piece of paper shall be printed with a phone number and SMS text used to charge the ticket or get information.

12. Whenever a SMS with valid recharge text is received, the corresponding ticket shall be extended by a pre-set amount of time.

13. When there is less than ten minutes remaining on a ticket, an informational SMS shall be sent to the phone number last used to recharge the ticket, if any.

14. It shall take less than one minute to print a ticket and pay it using SMS for 95% of users who are not familiar with the system.

                    6  7  8  9 10 11 12 13 14
Relative benefit    2  9  3  7  6  6  6  3  4
Penalty if missing  1  6  3  7  8  6  9  1  5
Cost of implement.  1  7  6  4  4  1  7  4  7
PRIORITY            2  8  0 10 10 11  8  0  2

Task 2:
                    6  7  8  9 10 11 12 13 14
Complete            -  -  -  -  -  -  -  -  -
Traceable           Y  Y  Y  Y  Y  Y  Y  Y  Y
Testable            Y  N  Y  Y  Y  Y  Y  Y  Y
Consistent          Y  Y  Y  Y  Y  Y  Y  Y  Y
Feasible            Y  Y  Y  Y  Y  Y  Y  Y  Y
Uniq.Determined     Y  Y  Y  Y  Y  Y  Y  Y  Y
Design Free         Y  Y  Y  Y  Y  Y  Y  Y  Y
“Shall”             N  Y  N  Y  Y  Y  Y  Y  Y