T3 - Use Case Description

Question 1

Explain the purpose of Use case Diagram

Answer 1

Providing a sequences of actions that leads successful and failure scenarios

Note: Use Case Description is not a part of the UML because it is not a graphical notation

Question 2

in use case description, Explain what is a goal

Answer 2

A brief description of the overview and purpose of the use case

Question 3

What are Scenarios?

Answer 3

A scenario describes a series of interactions between an actor and the system

Description of the
starting situation; a description of the normal
flow of events (main and exception);

Question 4

What is the difference between alternate and exception flow?

Answer 4

Exception flows are those events that prevent certain steps, or the entire use case,
from completing successfully.
Alternate flows are the conditional steps in the scenario of a use case. (Mainly if and else statements)

Question 5

When do we use sub-flows?

Answer 5

Subflow is the break down of a normal flow into multiple sub - flow to make it easier to understand

We use it when normal flow is too complex

Question 6

Discuss the difference between recoverable and non - recoverable extensions

Answer 6

Recoverable Extensions: The use returns back to the mainline

Non – recoverable extensions: The use case is terminated