# How to create a bridge model in OpenBrIM Platform?

OpenBrIM uses **parametric modeling** to define all bridges. Instead of drawing geometry manually, you define parameters that drive the entire model.

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## Parametric vs. Traditional Modeling

| Aspect             | Traditional Modeling                    | Parametric Modeling                                    |
| ------------------ | --------------------------------------- | ------------------------------------------------------ |
| **Input**          | Draw lines, surfaces, enter coordinates | Define parameters (span length, girder depth, etc.)    |
| **Making changes** | Manually update each affected element   | Change one parameter, everything updates automatically |
| **Reusability**    | Start from scratch each project         | Reuse components across projects                       |
| **Error risk**     | High (manual updates can be missed)     | Low (automatic propagation)                            |

{% hint style="info" %}
**How it works:** When you change a parameter (e.g., span length), OpenBrIM automatically updates all related elements—3D geometry, finite element model, drawings, and reports—in real-time.
{% endhint %}

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## The OpenBrIM Library

The OpenBrIM Library stores parametric components with built-in engineering relationships. This provides:

* **Transparent logic** — See how components relate to each other
* **Customization** — Modify components or create your own
* **Reusability** — Use the same components across multiple projects
* **Collaboration** — Share custom components with your team

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## Typical Workflow

| Step                    | Action                                                                                                                                |
| ----------------------- | ------------------------------------------------------------------------------------------------------------------------------------- |
| **1. Requirements**     | Work with OpenBrIM engineers to identify project needs and customize library components                                               |
| **2. Alignment**        | Import LandXML alignment data                                                                                                         |
| **3. Parameters**       | Enter bridge parameters in the spreadsheet                                                                                            |
| **4. Review**           | Check the model in 3D, FEA, and CAD views                                                                                             |
| **5. Analysis**         | Run finite element analysis and review results                                                                                        |
| **6. Design**           | Run specification checks and generate reports                                                                                         |
| **7. Quantity Takeoff** | Generate quantities with pay items for cost estimation                                                                                |
| **8. Export**           | Export to other FEA software to verify analysis results, or export 3D/2D models with pay items to meet agency submission requirements |

<figure><img src="https://openbrim.atlassian.net/wiki/download/attachments/2101641217/OpenBrIM%20Platform%20Brochure_Steel%20Tub%20Girder%20Bridge_a_pg_1-2.png?api=v2" alt="OpenBrIM workflow overview"><figcaption><p>OpenBrIM Platform workflow overview</p></figcaption></figure>

***

## Customization

Need a parameter that doesn't exist? You have two options:

1. **Customize the library yourself** — Modify existing components or create new ones
2. **Work with our team** — OpenBrIM engineers can add parameters to meet your requirements

Custom components become part of your library and can be reused across all future projects.


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