Engineering Simulation Supporting Certification

The Role of Verification, Validation and Uncertainty Quantification

Dr. Márton Gróza, 5^th of March 2026

This report draws on interviews conducted with the following members of the NAFEMS Community: Dr. Mohamed Besher Baradi (Robert Bosch), Dr. Rodney Dreisbach (NAFEMS), Biplob Dutta (Siemens Digital Industries Software), Dr. Frank Günther (Knorr-Bremse Railway Systems), Dr. Steve Howell (Abercus), Dr. William Oberkampf (Engineering Consultant), Dr. Fabio Santandrea (Volvo Group), Dr. Scott Shaw (MBDA), Dr. David Tanner (UK Ministry of Defence), Riccardo Testi (Piaggio Group), Louise Wright (NPL).

The report was reviewed by the Members of the ASSESS Certification Theme Committee: Joseph Banks (Piper Aircraft), Dr. Arianna Bosco (Siemens AG), Peter Coleman (Airbus Operations), Dr. Rodney Dreisbach (NAFEMS), Biplob Dutta (Siemens Digital Industries Software), Dr. Alexander Karl (Rolls-Royce Corporation), Prof. Trevor T. Robinson (Queen’s University Belfast), Dr. Scott Shaw (MBDA), Riccardo Testi (Piaggio Group).

Produced by NAFEMS, this report was supported by the Smart Design Innovation Network – Certification by Analysis community, convened and hosted by the NCC on behalf of the High Value Manufacturing Catapult (HVMC), and was reviewed by Andrew Patterson and Marc Funnel (NCC).

Certification by Analysis (CbA) broadly refers to a growing reliance on engineering simulation techniques to demonstrate compliance with requirements to external parties. Taken literally, the term suggests that certification is based solely on simulation results.

A more informative definition of CbA is when an independent authority accepts simulated evidence as part of the certification case. Simulation is more often understood as complementing, rather than completely replacing, established standards-based physical testing. Physical testing can only be safely replaced in cases where the underlying physics is well understood, and the simulation methods have been rigorously verified and validated.

While simulation is often assumed to be cheaper than physical testing, in safety-critical programmes the effort required to generate credible evidence can rival a conventional test campaign. The distinctive value of simulation is therefore not cost alone, but the ability to explore a far broader range of operating conditions than is affordable or safe in the physical world.

CbA starts with a regulator that considers the acceptance of simulation-based evidence.CbA is therefore not merely a technical challenge, but a strategic endeavour focused on building trust between the organisations performing simulations and the regulatory bodies responsible for public safety.

The goal is broad recognition of simulation-based evidence by regulators, built on the premise that simulation can deliver results of equal or greater reliability and coverage than experimental testing. A key enabler here is Verification, Validation and Uncertainty Quantification (VVUQ), which can turn simulation results into evidence. Verification checks that the computational model is solved correctly, and validation compares simulation results with physical data to show the model predicts reality to the required accuracy. Uncertainty Quantification (UQ) then assesses the impact of uncertainties on the simulation, such as variability in materials and loads, choices in modelling, or numerical errors.