Requirement diagram makerfrom plain language, free.

requirementDiagram
  direction LR

  requirement measure {
    id: 1
    text: "Measure patient temperature"
    risk: High
    verifymethod: Test
  }

  performanceRequirement accuracy {
    id: 1.1
    text: "Accurate to 0.1 degrees C"
    risk: High
    verifymethod: Test
  }

  functionalRequirement logging {
    id: 2
    text: "Log a reading every minute"
    risk: Medium
    verifymethod: Demonstration
  }

  interfaceRequirement sync {
    id: 2.1
    text: "Send logs to the hospital system"
    risk: Medium
    verifymethod: Inspection
  }

  designConstraint storage {
    id: 3
    text: "Keep 7 days of readings offline"
    risk: Low
    verifymethod: Analysis
  }

  physicalRequirement battery {
    id: 4
    text: "Run 48 hours on battery"
    risk: Medium
    verifymethod: Test
  }

  element sensor {
    type: "Thermistor probe"
  }

  element firmware {
    type: "Embedded software"
  }

  element gateway {
    type: "HL7 gateway"
  }

  element benchTests {
    type: "Bench test suite"
  }

  accuracy - refines -> measure
  logging - derives -> measure
  sync - refines -> logging
  storage - refines -> logging
  sensor - satisfies -> measure
  firmware - satisfies -> logging
  firmware - satisfies -> storage
  gateway - satisfies -> sync
  benchTests - verifies -> accuracy
  benchTests - verifies -> battery