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Prerequisites

The V-Model is a systems engineering framework where the left side represents decomposition (needs to requirements to design) and the right side represents integration testing (design verification, system verification, user need validation). The bottom of the V is where risk analysis connects both sides.

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The Traceability Chain

The solution implements an 8-entity, 8-relationship traceability graph. This walkthrough follows one path through it: diagram

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Step 1: Start with a User Need

  1. Navigate to the Requirements space
  2. Open the USER-NEEDS document
  3. Locate a user need, for example: “The infusion pump shall deliver fluid at the rate set by the clinician”
This user need sits at the top of the V-Model. It is linked to use steps via the address relationship and serves as the starting point for all downstream traceability.

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Step 2: Follow the Refinement to System Requirements

  1. Open the Whole RTM Sheet from the sidebar favorites
  2. Find your user need row in the User Needs column group (green headers)
  3. Look at the System Requirements column group (purple headers) — the PowerSheet shows system requirements that refine this user need
For example, the user need might refine into:
  • “SRS-001: The pump shall support flow rates from 0.1 to 999.9 mL/hr”
  • “SRS-002: The pump shall display the current flow rate on the LCD”
System requirements are constrained by document type (systemRequirementsSpecification). The RTM model ensures you can only link requirements from valid specification documents.

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Step 3: Follow to Design Requirements

Still in the RTM Sheet, look at the Design Requirements column group (blue headers):
  • SRS-001 might refine into: “DRS-001: The peristaltic pump mechanism shall accept rate commands via I2C at 100ms intervals”
  • SRS-002 might refine into: “DRS-002: The LCD controller shall update rate display within 200ms of rate change”
Design requirements are scoped by subsystem. The $context.source.document.subsystem constraint ensures that when linking back from a design requirement, only requirements from the same subsystem document appear in the picker.

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Step 4: Examine Risk Analysis at the Bottom of the V

  1. Navigate to the Risks space
  2. Open the HARA-ANALYSIS document in the risksheet
  3. Find risk records that assess use steps related to your user need (the assesses link connects risk records to use steps)
Each risk record captures:
  • Hazard: What could cause harm (from the Hazards Catalog)
  • Hazardous Situation: The specific scenario
  • Harm: The potential injury (from Standard Harms)
  • Risk Controls: Measures to reduce risk (linked via mitigates)

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Step 5: Trace Risk Controls to Requirements

Risk controls close the loop between risk analysis and requirements:
  1. In the HARA risksheet, locate the Requirements column
  2. This server-rendered column shows system and design requirements that implement the risk control
  3. The Verification Evidence column then shows test cases linked to those requirements
This two-hop traversal (Risk Control > Requirement > Test Case) provides the complete evidence chain required by ISO 14971 Clause 7.4.

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Step 6: Verify on the Right Side of the V

Navigate to the Testing space to see the three verification/validation tiers:
TierDocument PatternLink RoleTests In This Project
User Need ValidationUserNeedsValidationvalidates19 test cases
System VerificationSystemReqsVerification-SYS/SUB-*verifies82 test cases
Design VerificationDesignReqsVerification-SYS/SUB-*verifies47 test cases
  1. Open a SystemReqsVerification document (e.g., SystemReqsVerification-SYS-001)
  2. Find test cases that verify the system requirements you traced in Step 2
  3. Open the User Need Validation Sheet PowerSheet to see validation test cases linked to the original user need

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Verification

You have successfully traced a complete V-Model path when you can identify:
ArtifactLinkNext Artifact
User Needrefines (reverse)System Requirement
System Requirementrefines (reverse)Design Requirement
Risk RecordassessesUse Step (linked to User Need)
Risk ControlmitigatesRisk Record
System/Design RequirementimplementsRisk Control
Test CaseverifiesSystem/Design Requirement
Test CasevalidatesUser Need
The Whole RTM Sheet PowerSheet provides this entire traceability chain in a single interactive view. Use it for reviews, audits, and gap analysis.

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Next Steps