Which of the following documents best supports traceability in quality control?

• A. Checklists
• B. Design reviews
• C. Design calculations
• D. Checklists, design reviews, design calculations, and sign-off records.

Answer: (D)

Traceability in quality control means having a documented trail from the original requirements through design decisions, verification activities, and final approvals. Checklists ensure every required step and criterion is completed, providing concrete evidence of what was checked and when. Design reviews capture how the design was evaluated against requirements, recording decisions, issues found, and resolutions, linking design choices to the intended outcomes. Design calculations show the quantitative reasoning that demonstrates how the design meets specifications, tying requirements to technical justification. Sign-off records provide accountability and authorization, showing who approved what and when, sealing the traceability chain.

Relying on any single type of document leaves gaps in the trail. A complete, auditable chain comes from using all four together, which best supports traceability from requirements through design to verification and approval.