Best practices for data modeling and data cleaning in Power BI
This article outlines the best practices for data modeling and data cleaning in Power BI, which are critical for creating accurate and effective reports. It covers topics such as creating a star schema, removing unnecessary columns, using calculated columns, and establishing data refresh schedules.
The author of this article is EPAM senior software engineer Diego Messala.
Microsoft Power BI is a popular business intelligence tool that enables users to analyze, visualize, and share data. To get the most out of Power BI, it is essential to follow data best practices. In this article, we will discuss best practices for data modeling and data cleaning in Power BI, and provide an example use case for a sales department in a retail company.
Data modeling best practices
Data modeling is the process of designing the structure of the data used in a Power BI report. Here are some best practices for data modeling in Power BI:
Data cleaning best practices
Data cleaning is the process of identifying and correcting errors and inconsistencies in the data. Here are some best practices for data cleaning in Power BI:
Example use case: sales department in a retail company
Consider a sales department in a retail company as an example. The data sources used by the sales department include customer data, product data, and sales data. Here's how we can apply data best practices to the sales data:
Data Modeling
- Create a star schema with the sales data as the fact table and customer and product data as dimension tables.
- Remove unnecessary columns such as customer or product information that are not used in the report.
- Create calculated columns such as total sales, profit, and discount percentage in the data model.
- Use hierarchies and drill-downs to allow users to navigate through the data quickly.
- Use consistent naming conventions for tables, columns, and relationships.
- Document the data model to ensure that others can understand the structure of the data.
Data Cleaning
- Identify and fix data quality issues such as incorrect or missing customer data.
- Remove duplicates and fill in missing data such as missing product information.
- Combine data from multiple sources such as customer data, product data, and sales data.
- Transform data into a consistent format such as converting dates to a single consistent date format.
- Use data profiling to identify patterns and inconsistencies in the data.
- Establish a data refresh schedule to ensure that the data is up to date.
Following these best practices ensures that the data is modeled and cleaned efficiently and effectively, resulting in a report that is accurate and easy to understand. It's essential to note that the best practices identified above are not an exhaustive list and recommendations may vary depending on the specific requirements of the report.
Extra references
For those looking to take a deep dive into data modeling and data cleaning in Power BI, there are resources available. Here are two to get you started:
- "Data Modeling with Power BI" by Adam Aspin; and
- "Data Cleaning Features in Power BI" by Rushabh Shah.
Following best practices for data modeling and data cleaning in Power BI is critical for creating accurate, efficient, and effective reports. By creating a star schema, removing unnecessary columns and tables, and using calculated columns and measures, users can model their data in a way that is easy to navigate and analyze. By identifying and fixing data quality issues, removing duplicates, and filling in missing data, users can ensure that their data is accurate and up to date. By following these best practices, users can create compelling reports that provide meaningful insights into their data.