As DO-178B was updated to DO-178C it was decided that the increasingly popular model-based development should be made available to compliant applications, and that they should be addressed by a supplement, DO-331, “Model-Based Development and Verification Supplement to DO-178C and DO-278A”. 

This document explains how the approach was adopted for specification models or design models take the place of high-level and low-level requirements respectively, the extent to which model-based verification activities can be deployed, and where verification on the target is required.