Tableau → Power BI Migration

The pre step connects to the Tableau .twbx embedded .hyper data extracts, exports them as CSV files into [pipeline].working/data/, and hands them to the post-bind step so Power BI Desktop can see live data immediately after opening the converted project.

The converter itself does not require this step. Analyze and convert read the .twbx directly. This step only benefits the post-bind (data verification) workflow.

navis-ta-pbi-pre spec.toml

Reads [pipeline].input (workbook path) and [pipeline].working (staging folder). No additional [pre] keys required for Tableau.

Scan .twb / .twbx files to assess what can be automatically migrated before committing to a conversion.

navis-ta-pbi analyze spec.toml                  # Analyze all workbooks
navis-ta-pbi analyze spec.toml --path Sales.twbx  # Single workbook
navis-ta-pbi analyze spec.toml -o analysis.pdf    # Save report
navis-ta-pbi analyze spec.toml --summary-only     # High-level numbers only
navis-ta-pbi analyze spec.toml --no-recursion     # Top-level folder only

Submit the License Request PDF to navis@cepheusonline.com. The PDF embeds cryptographic fingerprints of your workbooks. Cepheus replies with a license file.

1. Run navis-ta-pbi analyze and save the License Request PDF
2. Email the PDF to navis@cepheusonline.com
3. Receive a license file back

[convert]
license = "license.json"

navis-ta-pbi verify-license spec.toml

navis-ta-pbi convert spec.toml
navis-ta-pbi convert spec.toml --output C:/Output  # Override output folder

What Navis produces

For each workbook: a .pbip folder (Power BI Project), plus a _CEC.zip Evidence Capsule.

How calculations are converted

Every DAX formula Navis produces has been individually tested against actual Tableau output to verify identical results. This isn’t approximate translation — it’s proven equivalence. If Navis encounters a calculation it cannot convert with proven accuracy, it flags it rather than guessing.

Windows only. The converter produces a .pbip project with the correct semantic model and DAX measures, but the M queries point to placeholder data sources. The post step writes the source data as CSV files alongside the project and repoints the M queries at those CSVs — so you can open the project in Power BI Desktop and see live data immediately.

Reads the .hyper data extracted during the pre step (from [pipeline].working/data/). No additional configuration required.

[post]
# No extra keys needed — data is read from [pipeline].working/data/

navis-ta-pbi-post spec.toml

After the post step, open the .pbip file in Power BI Desktop — all visuals will populate with data. Review the conversion, check the Evidence Capsule PDF for any fidelity gaps, and hand off to your data team.

Review the PDF report inside the Evidence Capsule for anything flagged:

• Data connections — connect to your production data source after import.
• Unmapped calculations — formulas without a proven equivalent yet; clearly marked so you can write them manually.
• Dashboard actions (filter, URL, highlight) — noted as fidelity gaps; need manual recreation.
• Custom images and decorative elements — not transferred.
• Tableau Server / Cloud features — live connections, user filters, etc. need manual reconfiguration.
• Gantt charts — no direct Power BI equivalent; flagged.
• Parameters — preserved as metadata; wire to Power BI slicers manually.
• Nothing is ever silently skipped. If Navis can’t convert something, it tells you.

Power BI Project folder

SalesDashboard/
  SalesDashboard.pbip              <-- open this in Power BI Desktop
  SalesDashboard.Report/
    definition.pbir
    report.json
  SalesDashboard.SemanticModel/
    definition.pbism
    definition/
      model.tmdl
      database.tmdl
      tables/
  _CEC.zip                         <-- Evidence Capsule

Open SalesDashboard.pbip in Power BI Desktop. The semantic model and all DAX measures are fully defined — you only need to point the data source at your production data.

The _CEC.zip Evidence Capsule contains the PDF audit report with formula-level conversion evidence, SHA-256 checksums, and any fidelity gaps.

Every conversion produces a _CEC.zip alongside the converted output. It contains:

• A signed PDF with formula-level translation evidence
• SHA-256 checksums of all input files
• A machine-readable JSON manifest of all conversions and fidelity gaps
• A timestamp and license reference

The capsule is tamper-evident: any modification to the converted output invalidates the checksums in the PDF. Keep _CEC.zip alongside your converted project as your audit record.

The Evidence Capsule PDF is cryptographically signed by Cepheus. The signature certifies:

• The workbooks that were analyzed match the license issued
• The conversion was performed by an authentic, unmodified Navis binary
• The formula translations are the ones Cepheus has validated

Signature verification does not require internet access. The public key is embedded in the license file.

Every command writes a structured log alongside the output. Log entries include:

• Per-workbook conversion decisions and fidelity gaps
• SHA-256 of each input file at conversion time
• Formula translation records (source expression → target expression)
• Any warnings or skipped elements

Logs are in JSON Lines format for easy ingestion into SIEM or audit tooling.

License errors

Common issues

For other issues: navis@cepheusonline.com

To analyze or convert a specific subset of workbooks, create a named pathlist in spec.toml:

[pipeline]
input   = "C:/Workbooks"
pathlist = ["Sales.twbx", "Finance.twbx", "HR.twbx"]

Each path in pathlist is resolved relative to [pipeline].input. Use this to run a focused subset without moving files or duplicating the spec.

CLI --path overrides pathlist when provided.