Comprehensive Tutorial: How to Instantly Transform Use Cases into UML Activity Diagrams and Reports

Using AI.Visual-Paradigm.com Tool (Free & Instant)

This tutorial will guide you step-by-step through the entire process of turning a textual use case into a professional UML Activity Diagram and a full written report — in just a few minutes.

Tool URL: https://ai.visual-paradigm.com/tool/use-case-to-activity-diagram/

Step 0: Access the Tool

  1. Open your browser and go to: https://ai.visual-paradigm.com/tool/use-case-to-activity-diagram/ No sign-up or login is required for basic use (you can use it completely free right away).

The page looks exactly like the screenshot you provided.

Step 1: Identify – Set Up Basic Information

Fill in the top section “Identify Your Use Case”

Fields:

  • Use Case Name (required) → e.g., “Withdraw Cash”
  • System (required) → e.g., “ATM System”
  • Primary Actor (required) → e.g., “Customer”
  • Secondary Actors (optional) → e.g., “Bank System”

Example:

  • Use Case Name: Withdraw Cash
  • System: ATM Machine
  • Primary Actor: Bank Customer
  • Secondary Actors: Bank Server

Click anywhere outside the fields or press Tab to continue.

Step 2: Describe – Write the Use Case in Simple Natural Language (Line-by-Line)

This is the most important part. The AI is extremely good at understanding plain English written line-by-line.

Best practices for writing:

  • Write one action per line
  • Start with the actor or system (e.g., “Customer inserts card”)
  • Use imperative form
  • Separate Main Success Scenario, Alternative Flows, and Exception Flows clearly with headings

Recommended structure inside the big text box

Use Case Description: Withdraw Cash
  • Name: Withdraw Cash
  • Actor: Customer (Primary)
  • System: ATM System
  • Purpose: To allow a customer to withdraw cash from an ATM using their account credentials and PIN.
  • Preconditions:
    • The customer must be authenticated (logged in) to the ATM system.
    • The customer’s account must have sufficient balance to cover the requested amount.
    • The ATM must be operational and have sufficient cash in the machine.
  • Postconditions:
    • The requested cash amount is dispensed to the customer.
    • The account balance is updated accordingly.
    • A receipt is printed (if applicable).
    • The transaction is recorded in the transaction history.
  • Flow:
    1. The customer inserts their card into the ATM.
    2. The system prompts the customer to enter their PIN.
    3. The customer enters the PIN and submits it.
    4. The system verifies the PIN and authenticates the customer.
    5. The customer selects the “Withdraw Cash” option.
    6. The system asks for the amount to withdraw.
    7. The customer enters the desired amount.
    8. The system checks if the balance is sufficient and if the machine has enough cash.
    9. If valid, the system dispenses the cash and updates the account balance.
    10. A receipt is printed (optional).
    11. The customer removes the card and exits.
  • Extensions (Optional Behaviors):
    • If the balance is insufficient, the system displays an error message and prompts the customer to enter a smaller amount.
    • If the machine runs out of cash, the system notifies the customer and suggests alternative options (e.g., balance check or cash advance).
    • A “Print Receipt” action may be triggered as an optional extension.
  • Included Use Cases:
    • Login (to authenticate the customer)
    • Verify PIN
  • Notes:
    • This use case is mandatory for all ATM transactions.
    • It must be executed in the context of a secure, authenticated session.
    • The system must validate inputs to prevent fraud or invalid transactions.
You can write as many alternative and exception flows as you need. The AI automatically detects and correctly places decision nodes, parallel actions, etc.

Step 3: Generate Diagram

After you finish writing the description:

Click the big blue button “Generate Diagram”

In less than 5 seconds you will see two tabs appear:

  1. Activity Diagram (Mermaid)
  2. Report

Step 4: View and Download the UML Activity Diagram

Switch to the “Activity Diagram” tab.

You will see:

  • A live preview of the UML Activity Diagram (perfectly formatted)
  • The raw Mermaid.js code in a box below

Options available:

  • Copy Mermaid code (for GitHub, GitLab, Notion, Obsidian, Mermaid Live Editor, etc.)
  • Download as SVG
  • Download as PNG
  • Zoom in/out

The diagram follows official UML 2.5 activity diagram notation (start/end, actions, decisions, forks/joins, swimlanes for actors if needed).

Step 5: View and Download the Professional Report

Switch to the “Report” tab.

The AI automatically generates a complete, well-structured requirements document that includes:

  • Use Case Name & ID
  • Actors
  • Preconditions & Postconditions (inferred)
  • Trigger
  • Main Success Scenario (numbered steps)
  • Extensions / Alternative Flows (with conditions)
  • Exception Flows
  • Business Rules (if detected)
  • Non-functional requirements (if mentioned)

You can:

  • Copy the entire report (Markdown or plain text)
  • Download as DOCX (Microsoft Word)
  • Download as PDF

Example of What You Get in Seconds (Withdraw Cash)

 

Bonus Tips for Best Results

  • Write in active voice and one step per line → highest accuracy
  • Use words like “if”, “when”, “unless” to trigger decision diamonds automatically
  • You can add <<include>> or <<extend>> relationships by writing them naturally
  • For multiple actors, mention the actor name at the beginning of the line: “Teller verifies customer ID”
  • The tool automatically creates swimlanes/partitions
  • Works perfectly with Agile user stories too: “As a customer, I want to withdraw cash so that I can have physical money”

Common Use Cases People Convert Daily

  • Login / Authentication
  • Register New User
  • Place Order (e-commerce)
  • Book Flight / Hotel
  • Submit Expense Report
  • Approve Purchase Request
  • Patient Check-in (healthcare)
  • Generate Invoice

Conclusion

You now know how to go from a plain-text use case → professional UML Activity Diagram + full report in under 3 minutes.

No installation No drawing skills required 100% free for unlimited use

Start now: https://ai.visual-paradigm.com/tool/use-case-to-activity-diagram/

Happy diagramming!

 

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