Lesson 5: User Scenarios#

Understanding User Journeys#

A User Scenario describes the series of steps a user takes to achieve a specific goal within your system. While static architecture diagrams show structure, user scenarios show behavior.

Why Model Scenarios?#

1. Validation: Ensures that all components required for a feature actually exist and are connected.
2. Clarity: Helps stakeholders understand how the system works from a user’s perspective.
3. Testing: Serves as a blueprint for integration and end-to-end tests.

Example Scenario: Buying a Ticket#

1. User searches for events.
2. User selects a ticket.
3. User enters payment details.
4. System processes payment.
5. System sends confirmation email.

🛠️ Sruja Perspective: Modeling Scenarios#

Sruja provides a dedicated scenario keyword to model these interactions explicitly. This allows you to visualize the flow of data across your defined architecture.

architecture "Ticketing System" {
    requirement R1 functional "User can buy a ticket"
    requirement R2 performance "Process payment in < 2s"

    // Define the actors and systems first
    person User "Ticket Buyer"
    
    system TicketingApp "Ticketing Platform" {
        container WebApp "Web Frontend"
        container PaymentService "Payment Processor"
        container EmailService "Notification Service"

        WebApp -> PaymentService "Process payment"
        PaymentService -> EmailService "Trigger confirmation"
    }

    // Define the scenario
    scenario BuyTicket "User purchases a concert ticket" {
        User -> WebApp "Selects ticket"
        WebApp -> PaymentService "Process payment"
        PaymentService -> EmailService "Trigger confirmation"
        EmailService -> User "Send email"
    }
}

By defining scenarios, you can automatically generate sequence diagrams or flowcharts that map directly to your code.