> For the complete documentation index, see [llms.txt](https://help.pesipiuma.app/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.pesipiuma.app/en/using-pesipiuma/preliminary-operations.md).

# Model Operations

Project sizes, pieces, and sections are created by the selected import method.

In Pesipiuma v3, you normally start by importing:

* A **DXF** file, with optional **RUL** grading data.
* **Excel** source files from a supported importer.

After import, use the editor to review and refine sizes, pieces, sections, coefficients, target weight, and report labels.

{% content-ref url="/pages/8TibUsEDtgeoHlSAlfSh" %}
[Manage Sizes](/en/using-pesipiuma/preliminary-operations/manage-sizes.md)
{% endcontent-ref %}

{% content-ref url="/pages/xJA1nJWg68fv0fjAVuz1" %}
[Manage Pieces](/en/using-pesipiuma/preliminary-operations/manage-pieces.md)
{% endcontent-ref %}

## Import data using the importers

Pesipiuma includes importers for DXF/RUL and CAD-generated Excel files.

{% content-ref url="/pages/DPSu8K9UviQX2COv18FZ" %}
[Using the Importers](/en/using-pesipiuma/using-the-importers.md)
{% endcontent-ref %}