abstract:Model based definition (MBD), also known as digital product definition (DPD), is the practice of using 3D digital data (such as solid models, 3D PMI and associated metadata) within 3D CAD software to provide specifications for individual components and product assemblies. The types of information included are geometric dimensioning and tolerancing (GD&T), component level materials, assembly level bills of materials, engineering configurations, design intent, etc.