When should relationships be created in Power BI?

Creating relationships in Power BI is essential when tables in the model have common fields, which allows for effective data analysis and visualization. These relationships enable Power BI to combine and correlate data from different tables, ensuring that the reports and dashboards reflect accurate and meaningful insights based on interconnected data.

When tables share a common field, establishing a relationship helps in creating a unified model where insights can be derived across multiple datasets. This is particularly essential for scenarios such as analyzing sales performance over regions, where both sales and region tables can be related through a common field like "Region ID". Without these relationships, Power BI cannot effectively interpret the data's interconnections, leading to incomplete analyses.

The creation of relationships is not limited to just external sources or single data sources; they are fundamental when dealing with multiple tables that require linking to ensure consistent and accurate reporting. Relationships also serve a purpose far beyond mere visual aids; they underpin the data logic that supports analytical processes throughout the Power BI environment.