Requirement use cases Flashcards
Use case modeling
Each use case represents a discrete task that involves external interaction with a system.
What is a use case diagram
Provide a graphical description of interactions between users and systems.
What are the components of the use case diagrams
Actors, use cases, connections, descriptions, preconditions, triggers
What are actors in use case diagrams?
The different roles that are related to the system
What are the two types of actors?
Primary actor - someone or something outside the system and is performing an action on the system.
Secondary actor - is acted on by the system.
What is description in the use case section?
Provides the overview
A description is just a few sentences or a paragraph in length and includes the goal and primary actor
What is a precondiction in use cases?
Defines all the conditions that must be true (state of system) for the trigger to cause the initiation of the use case.
What is stimulus (triggers)
Describes the event that causes the use case to be initiated
How to handle when trigger happens but the precondition is not met?
1) handle the error within use case (as an exception)
2) put all the preconditions in the trigger
What is the basic flow of events:
Each use case should convey a primary scenario, or typical course of events, also “happy path”
Conveyed as a course of events in numbered steps.
What is an alternative path?
step or a sequence following different steps compared to happy path, but the goal IS reached.
Example “The system recognizes the user’s cookies”
What are post-conditions
Post conditions describes the state when the use cases completes - changes in the state of the system.
Basically, what happens when condition is met
What are extensions
Used to make optional interactions explicit or to handle exceptional cases
What are inclusions?
When you want to include another use case without writing it all over again. such as a “validate balance”
What is a Use case
A use case is a technique for documenting the potential requirements of a new system or software change.
Each use case provides one or more scenarios on how the system should interact with the end user or another system to achieve a specific business goal.
