Designcenter NX | How to | Moving from drawing-based engineering to MBD

Moving from drawing-based engineering to MBD (Designcenter NX)

What MBD is

Model-Based Definition (MBD) uses the 3D CAD model as the single master source for design, manufacturing, assembly, and inspection instead of separate 2D drawings. Product and Manufacturing Information (PMI) — dimensions, tolerances, annotations, GD&T — is embedded in the 3D model file.

PMI = dimensions, tolerances, annotations, GD&T embedded in the 3D model

Workflow and tools demonstrated

Tools used:

• Designcenter NX (Siemens NX environment)
• MBD Navigator

Convert to PMI command (Designcenter NX) — options:

• Convert all drawing content
• Convert a specified sheet
• Convert selective views
• Select individual drawing dimensions/GD&T to transfer into the 3D model

Additional notes:

• Supports both master-model drawings and non-master-model drawings
• Can be run in batch mode
• Result: converted PMI appears as original PMI entities and corresponding views (section views, user-defined views, top view) in the MBD Navigator

Packaging and data exchange

Provide a technical data package (TDP) including:

• 3D CAD model with necessary PMI (NX .prt, Parasolid, IGES, STEP — specifically STEP AP242 for PMI support)
• Optional published formats: 3D PDF or JT+PDF (created via Designcenter NX Publish / Publish 3D PDF)

Supported exchange files:

• NX part (.prt)
• Parasolid
• IGES
• STEP AP242 (for PMI)

Publishing process

Typical publish workflow:

1. Choose template (prebuilt or custom with embedded information)
2. Select views and output path
3. Attach CAD files
4. Fill metadata (part number, description, design date, designer)
5. Execute publish
6. Review publish log (shows output paths and attached files)

Outputs:

• 3D PDF, JT+PDF, IGES, STEP, etc.
• Outputs can be combined into a single ZIP (for example: 3D PDF + IGES + STEP)

3D PDF behavior (Adobe Acrobat Reader)

• Main viewport plus a carousel of selectable views
• Views are 3D and interactive
• Published PMI is interactive — selecting a dimension or GD&T highlights the corresponding geometry

Key recommendations & analysis

• Only include the PMI necessary for manufacturing and inspection — not every drawing dimension/GD&T needs conversion. The 3D model itself is part of the deliverable.
• Adopt a roadmap approach:
  • Start by converting existing drawing PMI in a sandbox or supplier scenario
  • Validate results and iterate before full adoption
• Benefits of MBD when executed with planning and validation:
  • Clearer communication
  • Fewer handoffs and errors
  • Improved efficiency
  • Higher accuracy and quality
  • Competitive advantage

Resources / features highlighted

• Designcenter NX: Convert to PMI, Publish 3D PDF / JT+PDF, batch conversion
• MBD Navigator: inspect converted PMI and views
• Supported exchange files: NX part, Parasolid, IGES, STEP AP242
• 3D PDF viewer: Adobe Acrobat Reader for interactive delivery

Main speaker / source

Sam Kuan — Siemens Product Engineering Software Marketing Team