Requirement Diagram

Requirement diagrams help visualize system requirements and their relationships. They're useful for documenting system specifications and dependencies.

Syntax

Basic Elements

• Requirements: requirement [Name] { [Properties] }
• Elements: element [Name] { [Properties] }
• Relationships:
  • Contains: contains
  • Copies: copies
  • Derives: derives
  • Satisfies: satisfies
  • Verifies: verifies
  • Refines: refines
  • Traces: traces

Basic Example

Code:

requirementDiagram
    requirement test_req {
        id: 1
        text: The system shall do something
        risk: high
        verifyMethod: test
    }

    element test_entity {
        type: simulation
    }

    test_entity - satisfies -> test_req

Ctrl + Enter|

Advanced Example

Here's a more complex requirement diagram for a login system:

Code:

requirementDiagram
    requirement UserAuth {
        id: REQ-001
        text: System must implement user authentication
        risk: medium
        verifyMethod: test
    }

    requirement SecureLogin {
        id: REQ-002
        text: Users must securely log in to the system
        risk: high
        verifyMethod: test
    }

    requirement PasswordPolicy {
        id: REQ-003
        text: Passwords must meet security requirements
        risk: high
        verifyMethod: test
    }

    element AuthService {
        type: service
    }

    element SecurityModule {
        type: module
    }

    AuthService - satisfies -> UserAuth
    SecurityModule - satisfies -> SecureLogin
    SecurityModule - satisfies -> PasswordPolicy
    SecureLogin - contains -> PasswordPolicy

Ctrl + Enter|

Requirement Properties

Requirements can have these properties:

• id: Unique identifier
• text: Description
• risk: Risk level (low, medium, high)
• verifyMethod: Verification method (test, inspection, demonstration)

Relationship Types

Code:

requirementDiagram
    requirement Req1 {
        id: 1
    }
    requirement Req2 {
        id: 2
    }
    requirement Req3 {
        id: 3
    }
    requirement Req4 {
        id: 4
    }

    Req1 - contains -> Req2
    Req1 - traces -> Req3
    Req1 - refines -> Req4

Ctrl + Enter|

Element Types

Elements can be of different types:

Code:

requirementDiagram
    element UI {
        type: ui
    }
    element API {
        type: service
    }
    element Database {
        type: database
    }
    
    requirement SystemReq {
        id: SR-001
    }

    UI - satisfies -> SystemReq
    API - satisfies -> SystemReq
    Database - satisfies -> SystemReq

Ctrl + Enter|

Styling

The diagram automatically:

• Formats requirement boxes
• Shows relationship types
• Displays element types
• Organizes the layout

Tips

• Use clear and unique IDs
• Write concise requirement descriptions
• Specify appropriate risk levels
• Include verification methods
• Show meaningful relationships
• Group related requirements
• Use appropriate element types
• Keep the diagram hierarchy clear