Use case diagrams in Software Engineering - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Actors in Use Case Diagrams

In a use case diagram, what does an actor represent?

A A detailed description of system requirements

B A specific function or feature of the system

C A graphical symbol used to connect use cases

D A system or external entity that interacts with the system

💡 Hint

Think about who or what communicates with the system from outside.

An actor in a use case diagram represents an external entity, such as a user or another system, that interacts with the system to achieve a goal.

📋 Factual

intermediate

Symbols Used in Use Case Diagrams

Which symbol is typically used to represent a use case in a use case diagram?

A Oval or ellipse

B Rectangle

C Triangle

D Diamond

💡 Hint

It looks like an egg shape or stretched circle.

Use cases are represented by ovals or ellipses to show the actions or services the system provides.

🔍 Analysis

advanced

Identifying Relationships in Use Case Diagrams

Consider a use case diagram where one use case includes another use case. What does this include relationship mean?

A The included use case is optional and may or may not be executed

B The included use case replaces the base use case entirely

C The base use case always calls the included use case as part of its process

D The two use cases are unrelated and independent

💡 Hint

Think about when the included use case happens during the base use case.

An include relationship means the base use case always executes the included use case as part of its steps.

❓ Comparison

advanced

Difference Between Extend and Include Relationships

What is the main difference between extend and include relationships in use case diagrams?

A Include is mandatory; extend is optional and happens only under certain conditions

B Extend is mandatory; include is optional and happens only under certain conditions

C Both are mandatory and always executed together

D Both are optional and never executed

💡 Hint

Consider when each related use case is executed.

Include means the included use case always runs; extend means the extending use case runs only if certain conditions are met.

❓ Reasoning

expert

Determining the Number of Use Cases in a Diagram

A use case diagram shows 3 actors and 5 use cases. Two use cases are connected by an extend relationship, and one use case includes another. How many unique use cases are represented in the diagram?

A 6

B 5

C 4

D 7

💡 Hint

Think about whether include or extend relationships add new use cases or just connect existing ones.

Include and extend relationships connect existing use cases; they do not add new unique use cases. So the total remains 5.