Requirement Diagram

Back to Style Guide — Read the style guide first for emoji, color, and accessibility rules.

Syntax keyword: requirementDiagram Best for: System requirements traceability, compliance mapping, formal requirements engineering When NOT to use: Informal task tracking (use Kanban), general relationships (use ER)

Exemplar Diagram

mermaid

requirementDiagram

    requirement high_availability {
        id: 1
        text: System shall maintain 99.9 percent uptime
        risk: high
        verifymethod: test
    }

    requirement data_encryption {
        id: 2
        text: All data at rest shall be AES-256 encrypted
        risk: medium
        verifymethod: inspection
    }

    requirement session_timeout {
        id: 3
        text: Sessions expire after 30 minutes idle
        risk: low
        verifymethod: test
    }

    element auth_service {
        type: service
        docref: auth-service-v2
    }

    element crypto_module {
        type: module
        docref: crypto-lib-v3
    }

    auth_service - satisfies -> high_availability
    auth_service - satisfies -> session_timeout
    crypto_module - satisfies -> data_encryption

Tips

Each requirement needs: id, text, risk, verifymethod
id must be numeric — use id: 1, id: 2, etc. (dashes like REQ-001 can cause parse errors)
Risk levels: low, medium, high (all lowercase)
Verify methods: analysis, inspection, test, demonstration (all lowercase)
Use element for design components that satisfy requirements
Relationship types: - satisfies ->, - traces ->, - contains ->, - derives ->, - refines ->, - copies ->
Keep to 3–5 requirements per diagram
Avoid special characters in text fields — spell out symbols (e.g., "99.9 percent" not "99.9%")
Use 4-space indentation inside { } blocks

Template

mermaid

requirementDiagram

    requirement your_requirement {
        id: 1
        text: The requirement statement here
        risk: medium
        verifymethod: test
    }

    element your_component {
        type: service
        docref: component-ref
    }

    your_component - satisfies -> your_requirement