Guides
The defects behind most wrong numbers in Power BI.
Each guide explains one recurring problem: what it is, how it shows up in a report, how to fix it, and which of the audit's checks catch it.
Bidirectional relationships: when they silently corrupt totals
Why 'both directions' cross-filtering on a dimension breaks counts and totals, how to see it in a report, and what to use instead.
6 min read
Fact table on the 'one' side: the cardinality mistake that breaks every slicer
How a relationship declared the wrong way round turns a dimension into a filter that does nothing, and how to spot it before users do.
5 min read
Share of total in DAX: ALL, ALLSELECTED and the measure that always returns 100%
The three ways a percentage-of-total measure goes wrong, why the denominator must clear the dimension and not the fact, and a pattern that survives slicers.
7 min read
Refresh works on your laptop and fails in the Service
Local file paths, hardcoded servers and machine-specific settings inside Power Query, and how to make a model portable before publishing.
5 min read
Time intelligence without a date table: the YoY that looks right and isn't
Why SAMEPERIODLASTYEAR and DATESYTD need a marked, contiguous date table, and the two silent errors you get without one.
6 min read
Currency conversion at totals: SELECTEDVALUE, blended rates and the SUMX you actually need
Why a converted amount is right on every row and wrong on the total, and the row-level pattern that fixes it without scanning the fact table twice.
7 min read