Question

2. [2 marks] [2 marks] (a) Is the following statement true or false? Justify your answer. "A use case diagram describes a sequence of use cases representing the behaviour of the system when interacting with its environment (i.e., the actors)." (b) Is the following statement true or false? Justify your answer. "Structural models display the organisation of a system in terms of what the system does." (c) Is the following statement true or false? Justify your answer. "A good design in terms of modularity should demonstrate: tight coupling and high cohesion." The following scenario is related to the next two parts of this question. Consider a simple system to manage appointments in a doctor's practice. The systems shall consist of four basic entities. Each of the three entities, namely, doctor, staff and patient, are identified in terms of the name, address, phone and date of birth. In addition, patient records are associated with patients, and doctor's diaries are associated with doctors. The fourth entity captures the appointments, which are identified in terms of the date and time they take place. Members of staff at the practice are responsible for making and [2 marks] - 3 - cancelling appointments when a patient contacts them, and handling the medical history of patients. When making an appointment, a staff member requires the patient details. For cancelling an appointment, a staff member requires also the patient details plus the date of the appointment. For making and cancelling appointments, the diary of the doctor needs to be updated. When making appointments, doctors request to staff members the medical history of the patient.

Answer 1

2. (a)  The statement made about the use case diagram in which user interacts with different use cases.So the statement is referred as True. The confusing part in the above statement is 'sequence of use cases'  which makes the definition best suits to sequence diagram, but the actual portion of the definition about use case diagram elaborates further in 'The behaviour of the system when interacting with its environment'.

(b) The statement made is about the structural model and it is referred to as False because structural models are defined as structure of the system and the dynamic models are treated as organisation of the system.

(c) The statement made above is treated as False because for a good software designing model requires a loose coupling and high cohesion.Tight coupling is treated as bad as per the designing requirement.So tight coupling and high cohesion will not best suits for good design modularity.

(d) UML class diagram

DOCTOR STAFF + name: string + address: string + phone: int + doctor_diary: s1 + name: string + address: string + phone: int «interface update_diary(void) + medical_history(string): string + make_appointment(string): string + cancel_appointment(string): string + medical_record(string): string FOURTH ENTITY + date/time: Date + application_date(string) PATIENT name: string + address: string + phone; int patient_records(string): string

(e) UML Sequence diagram

f Boundary Object doctor :fourth entity staff PATIENT interface make_appoinment update_diary() cancel_appountment application_date() medical_record Text medical_history patient_records