Question #1

Your are developing a software system to support a gas station. The owner of a gas station has given you the following description.

Before being able to pump gas, a user has to insert his/her credit card in the card reader and select the pre-payment option to authorize the fill-up amount of gas. The pre-payment option performs several operations in the background, such as verifying that the card is not damaged, connecting to the credit card processing system, to ensure that the card is not reported stolen, the available balance on the card is sufficient to cover the gas purchase and to charge the card for the pre-payment amount.

Once the payment is approved, the user picks up the nozzle from the holster and starts fueling. The pump shows in different displays, the amount of fuel has been already pumped, the total $ amount and the number of liters left until the prepaid amount is reached. Once the prepaid amount is reached, fueling stops, the user returns the nozzle and a receipt is printed for the prepaid amount and the fueling is completed. In a case of a problem during the fueling, the system will stop the fueling and refund the credit card for the non-used amount.

1.Create a domain model for the above gas station problem

2.Create a full-dressed scenario for the fueling use case

3.Create a sequence diagram for the above scenario