Concept Notes – UML Use Case Diagram
- UML (Unified Modeling Language): A standard way to visualize software systems.
- Use Case Diagram: Represents the functional requirements of a system from the user’s perspective.
🔹 Components of Use Case Diagram
- Actors: External entities (users, systems, devices) interacting with the system.
- Use Cases: Functions or services the system provides.
- System Boundary: Rectangle that defines the scope of the system.
- Relationships:
- Association (―): Connects actors with use cases.
- Include (<<include>>): A mandatory use case called within another.
- Extend (<<extend>>): Optional/conditional functionality.
- Generalization (arrow): Inheritance relation between actors/use cases.
🔹 Purpose of Use Case Diagram
- Identifies system requirements.
- Helps communicate between stakeholders and developers.
- Used in requirement analysis phase.
⚙️ Example – Use Case Diagram Explanation
Suppose we design an Online Banking System:
- Actors: Customer, Bank Server, Admin.
- Use Cases: Login, View Balance, Transfer Money, Generate Report.
- Relations:
- Customer → Login → View Balance / Transfer Money.
- Admin → Generate Report.
- Transfer Money <<include>> Login.
🔢 Key Points to Remember
- Actor is always outside the system.
- Use cases are shown as ellipses.
- System boundary is a rectangle.
- Arrows and stereotypes (
<<include>>,<<extend>>) must be clearly labeled.
🔟 10 Most Expected MCQs – ECET 2026 (SE – UML Use Case)
Q1. UML stands for:
A) Unified Modeling Language
B) Universal Modeling Language
C) User Machine Language
D) Unified Modern Logic
Q2. Which diagram shows system functionality from user’s perspective?
A) Class Diagram
B) Use Case Diagram
C) Activity Diagram
D) Sequence Diagram
Q3. Use cases are represented by:
A) Rectangle
B) Ellipse
C) Diamond
D) Circle
Q4. Actors in a Use Case Diagram represent:
A) Functions of the system
B) External entities interacting with the system
C) Database entities
D) None
Q5. Which relationship represents mandatory inclusion of one use case in another?
A) Extend
B) Generalization
C) Association
D) Include
Q6. Extend relationship is used for:
A) Optional functionality
B) Mandatory functionality
C) Actor generalization
D) None
Q7. Which of the following is NOT a component of Use Case Diagram?
A) Actor
B) Use Case
C) Database Table
D) System Boundary
Q8. Generalization in actors indicates:
A) Inheritance
B) Association
C) Aggregation
D) Extension
Q9. In UML, a system boundary is represented by:
A) Ellipse
B) Rectangle
C) Diamond
D) Hexagon
Q10. The primary purpose of a Use Case Diagram is:
A) Testing system performance
B) Showing system requirements from user view
C) Database design
D) Coding
✅ Answer Key (Plain Table)
| Q.No | Answer |
|---|---|
| Q1 | A |
| Q2 | B |
| Q3 | B |
| Q4 | B |
| Q5 | D |
| Q6 | A |
| Q7 | C |
| Q8 | A |
| Q9 | B |
| Q10 | B |
🧠 Explanations of All Answers
- Q1 → A: UML = Unified Modeling Language.
- Q2 → B: Use Case Diagram shows functionality from the user’s perspective.
- Q3 → B: Use cases are drawn as ellipses.
- Q4 → B: Actors represent external entities (user/system).
- Q5 → D: Include is mandatory.
- Q6 → A: Extend is optional functionality.
- Q7 → C: Database table is not a UML component.
- Q8 → A: Generalization means inheritance.
- Q9 → B: System boundary = rectangle.
- Q10 → B: Main aim is requirement analysis from user’s view.
🎯 Why Practice Matters for ECET 2026
- Software Engineering concepts like UML are repeated every year in ECET.
- 1–2 direct questions come from Use Case Diagrams.
- Helps not only in exams but also in real-world requirement analysis & interviews.
📲 Join Our ECET Prep Community
For daily MCQs, solved examples, and video lessons:
👉 @LearnNewThingsHub
