How often Use case diagrams is asked

Where it was asked

• Oct/Nov 202227 marks
• May/Jun 202128 marks
• Oct/Nov 202029 marks

The questions

1. Oct/Nov 2022, Q5.112 marks

   A case study is given for use in both 5.1 and 5.2: The shipping department receives all shipments relating to outstanding purchase orders. When the clerk in the shipping department receives a shipment, he or she locates the outstanding purchase order corresponding to those items. The clerk then sends out multiple copies of the shipment packing slip: one copy goes to Purchasing, and that department updates its records to show that the purchase order has been fulfilled; a second copy goes to Accounting so that payment can be processed; a third copy goes to the requesting in-house customer so that he or she can receive the shipment. Once payment has been made, the Accounting department sends a notification to Purchasing. When Purchasing receives these additional confirmations, it closes the purchase order as fulfilled and paid. Using the shipping department scenario described (where the shipping clerk matches shipments to outstanding purchase orders and distributes packing slip copies to Purchasing, Accounting and the in-house customer, with Accounting later notifying Purchasing so that it can close the order as fulfilled and paid), draw a use case diagram that represents this scenario.

2. Oct/Nov 2022, Q5.215 marks

   A case study is given for use in both 5.1 and 5.2: The shipping department receives all shipments relating to outstanding purchase orders. When the clerk in the shipping department receives a shipment, he or she locates the outstanding purchase order corresponding to those items. The clerk then sends out multiple copies of the shipment packing slip: one copy goes to Purchasing, and that department updates its records to show that the purchase order has been fulfilled; a second copy goes to Accounting so that payment can be processed; a third copy goes to the requesting in-house customer so that he or she can receive the shipment. Once payment has been made, the Accounting department sends a notification to Purchasing. When Purchasing receives these additional confirmations, it closes the purchase order as fulfilled and paid. Using the same shipping department scenario (the clerk receiving shipments, matching them to outstanding purchase orders, distributing packing slip copies to Purchasing, Accounting and the in-house customer, Accounting processing payment and notifying Purchasing, and Purchasing closing the order as fulfilled and paid), draw an activity diagram that represents this scenario.

3. May/Jun 2021, Q2.110 marks

   Drawing on your knowledge of use cases, identify and describe five (5) guidelines relating to actors that must be considered when designing a use case diagram.

4. May/Jun 2021, Q4.118 marks

   This question refers back to the airport check-in narrative used in Question 3: a passenger arrives at the airport and approaches the airline desk to check in, presenting a ticket which passenger services verifies for validity. If the ticket is valid, the airline issues a boarding pass that allows the passenger to enter the restricted area of the airport and board the airplane for a specific flight; if invalid, the passenger cannot fly and is referred to booking/reservation services instead. The boarding pass shows the passenger's details, the flight number, the seat number, and the scheduled date and time of departure. While the passenger boards the plane, airline staff simultaneously load (check in) the passenger's luggage onto the airplane, organising it by luggage number; passengers who only carry hand luggage have none of their bags loaded with the other passengers' luggage. Once all passengers have boarded, the air traffic controller instructs the pilot to prepare for take-off and to taxi the airplane to the designated runway for departure. Using the airport check-in narrative provided in Question 3, draw a use case diagram that models the system described.

5. Oct/Nov 2020, Q3.114 marks

   Candidates must study a case study narrative about drone-based medicine delivery and then answer the sub-questions that follow. The narrative explains that ACM Communications reported at the end of 2019 that a high-value commodity which makes strong economic sense to deliver by drone is medicine, a concept also known as 'leapfrog' technology. The market need is clear: for perishable medical samples or life-saving vaccines, speed is critical, and aerial drones are well suited to crossing crowded or hard-to-reach areas, as is the case in the rural areas of KwaZulu-Natal. As a pilot study, Ngwelezane Hospital is used as a hub to distribute medicines to nearby remote areas using drones. When a nurse at a clinic makes a diagnosis requiring emergency medication, she immediately reports to the administration assistant, who sends a text message to Ngwelezane Hospital Services (NHS). This text message contains information about the patient, the diagnosis, and supporting facts about the emergency. The clinic staff are structured so that the nurse can be regarded as a type of administration assistant, since she can both diagnose patients and, in certain cases, send messages to NHS; however, the administration assistant herself is not permitted to diagnose patients even though she is a qualified nurse. Once Hospital Services receives the message, they inform and authorise the drone pilot to fly. The pilot performs a pre-flight check on the drone, which always includes checking the weather conditions. If the drone experiences problems during flight, the pilot takes manual control, overriding the automated functions to ensure the drone is delivered and returned safely. Occasionally, even while under manual override, pilots suffer from pilot fatigue, which becomes a risk; whenever this occurs, counter measures must be taken, such as requesting assistance from other pilots. As part of the 'Pre-flight Check' use case, the pilot initialises the settings via the drone's interface, and the drone/controller validates these initial settings. After validation, the pilot initialises the mapping sequences, and at the same time the supervisor loads and secures the load. Once this is complete, the drone runs the auto-mapping sequence, checking the traced path; if the path contains unexplored areas, the drone re-runs the auto-mapping settings, otherwise it updates the controller settings. The system then informs the pilot that the mapping sequence is complete and reports its status, after which the pilot shuts down the system via the interface. Using the drone delivery narrative about Ngwelezane Hospital Services, the nurse, the administration assistant, the drone pilot, the supervisor and the drone/controller, draw a use case diagram that captures the actors and use cases described in the scenario.