John Kerski has a use for user-defined functions:
Reuse is a very important term in DataOps. It is defined as the practice of leveraging existing components, code, or processes across multiple projects to reduce redundancy and improve consistency.
However, when it comes to Power BI, reusing DAX measures across projects was a difficult ‘copy and paste’ job. For my teams, we used DAX measures to help with testing our semantic models, but ensuring consistent testing conventions (and standard schemas of the tests) required lots of manual review.
Thankfully, that changed in late 2025 when Microsoft introduced User Defined Functions (UDFs) for Power BI. In this article, I’ll demonstrate how to use UDFs for testing, plus how to standardize the way teams test their models.
Click through to see how.