Basics of UML

📌 What is UML?

UML (Unified Modeling Language) is a standardized visual modeling language used to visualize, specify, construct, and document the structure and behavior of software systems.

💡 Purpose:

• Represent system architecture and design.

• Communicate system components, relationships, and processes.

• Document software requirements and designs clearly.

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⚙️ Why UML is Important for Business Analysts (BA)?

• Helps capture and clarify requirements.

• Bridges the gap between business needs and technical solutions.

• Assists in visual communication with stakeholders and developers.

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🎯 Main Types of UML Diagrams

UML diagrams are broadly divided into two categories:

Type	Purpose	Example Diagrams
1. Structure Diagrams	Show the static structure of the system	Class, Object, Component, Deployment
2. Behavior Diagrams	Show the dynamic behavior over time	Use Case, Sequence, Activity, State

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✅ Common UML Diagrams Used by Business Analysts

1. Use Case Diagram (Behavior)

• Purpose: Shows interactions between users (actors) and system functionalities (use cases).

• Key elements:

  • Actors (e.g., user, admin)

  • Use Cases (e.g., "Place Order", "Login")

  • System boundary

• Example:

scssCopyEdit[Customer] ----> (Place Order)
[Admin] ------> (Manage Products)

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2. Activity Diagram (Behavior)

• Purpose: Shows workflow or process flow (step-by-step activities).

• Key elements:

  • Start/End nodes

  • Activities (actions)

  • Decisions/branches

  • Parallel activities

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3. Sequence Diagram (Behavior)

• Purpose: Shows interactions between objects in a sequence over time (message flow).

• Key elements:

  • Actors/Objects

  • Messages (arrows)

  • Lifelines (dotted lines)

• Example:

pgsqlCopyEditUser -> System: Login Request
System -> DB: Validate Credentials
DB -> System: Return Result
System -> User: Show Dashboard

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4. Class Diagram (Structure)

• Purpose: Represents system classes, attributes, methods, and relationships.

• Key elements:

  • Classes (e.g., Customer, Order)

  • Attributes (e.g., name, ID)

  • Methods/Operations (e.g., createOrder())

  • Relationships (e.g., association, inheritance)

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🎥 Simple Example: Use Case Diagram

diffCopyEditActor: Customer
Use Cases: 
- Browse Products
- Add to Cart
- Checkout

scssCopyEdit[Customer] ---> (Browse Products)
[Customer] ---> (Add to Cart)
[Customer] ---> (Checkout)

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🔑 Benefits of Using UML

Benefit	Explanation
Clarity	Visualizes complex systems simply
Standardization	Follows an industry-standard approach
Communication	Improves understanding among stakeholders
Documentation	Helps in maintaining project artifacts
Analysis and Design	Aids in both business analysis and system design

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🚀 Summary of UML Basics

Aspect	Details
Definition	Unified Modeling Language for visual modeling
Main Categories	Structure and Behavior diagrams
Common Diagrams for BA	Use Case, Activity, Sequence, Class
Purpose	Clarify requirements, design systems, document processes