Overview
ISO 21143:2020 - Technical product documentation - Requirements for digital mock-up virtual assembly test (VAT) for mechanical products - specifies requirements for conducting a digital mock‑up virtual assembly test prior to physical production. The standard applies to 3D nominal models with theoretically exact dimensions and sets out a structured VAT workflow (preparation, implementation, review) to verify mechanical interface compatibility, detect interferences, and validate assembly feasibility and ergonomics.
Key topics and technical requirements
- VAT process and workflow
- Three phases: preparation, implementation, review.
- Emphasis on test planning, model certification, environment configuration and closed‑loop verification.
- Test plan components
- Test objectives, tasks, methodologies, process flow, test bill of materials (BOM), and schedule.
- Model preparation
- Product models (allowing controlled simplification and lightweighting while preserving key geometry and kinematics).
- Environment models (shop floor, tooling, fixtures).
- Virtual operator models (ideal human models for ergonomics).
- Model qualification and documentation requirements.
- VAT implementation requirements
- Interference inspection (static and dynamic): detect parts occupying the same space or unacceptable clearances.
- Assembly feasibility analysis: analyze assembly sequences, paths and procedures; ensure movement mechanisms function correctly.
- Ergonomics evaluation: use virtual operators to assess human factors and optimize assembly operations.
- Review and reporting
- Validate that preparation, plan, process and report requirements are met; document findings and corrective actions.
Practical applications
- Early detection and resolution of fit, clearance and interference issues before physical prototyping.
- Validation of mechanical interfaces across units, sub‑systems and integrated products.
- Optimization of assembly sequences and shop‑floor procedures to improve on‑site assembly efficiency.
- Ergonomics assessment to reduce workplace risk and improve operator accessibility.
- Support for reducing prototype cost and shortening product development cycles through virtual assembly simulation.
Who uses this standard
- Design and mechanical engineers performing CAD/CAM and DMU (digital mock‑up) activities
- Manufacturing and process engineers planning assembly lines and tooling
- Technical product documentation teams responsible for compliant design deliverables
- Quality, validation and systems engineers coordinating supplier integration and pre‑production testing
Related standards
- ISO 17599 - General requirements of digital mock‑up for mechanical products (referenced)
- ISO 29845 - Technical product documentation - Document types (referenced)
ISO 21143:2020 is a practical standard for organizations implementing virtual assembly testing and assembly simulation to improve product readiness, reduce on‑site issues, and streamline production validation.