Building the Foundation: Designing the Data Model in Power BI : Part 3

Masego
3 min readApr 30, 2024

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Welcome Back to Our Power BI Series!

Previous article : Mastering Data Cleaning and Transformation with Power Query at MavenTech: Part 2

In the previous articles, we took you through setting up a Windows VM on Azure and the intricate steps involved in cleaning and transforming our CRM Sales Performance data using Power Query. Now that our data is clean and primed for analysis, it’s time to dive into creating a robust Power BI data model. This article will guide you through the design of our data model and share some best practices that can help ensure efficiency and scalability.

Why is a Good Data Model Important?

A data model serves as the blueprint of your analysis. It defines the structure of how data is connected and processed, influencing performance, usability, and the accuracy of insights you can derive. A well-designed data model is crucial for efficiently handling large volumes of data and ensuring that your Power BI reports are both fast and reliable.

Designing the Data Model in Power BI

Creating a data model in Power BI involves defining tables, relationships, measures, and dimensions that reflect our business operations and objectives.

Here’s how we approached it:

  1. Establishing Relationships: Our CRM data consists of multiple tables — sales_teams, sales_pipeline, products, and accounts. Setting up relationships between these tables allows us to perform comprehensive analyses across different data points. For example, linking account in the sales_pipeline with account in the accounts table lets us analyse sales information by other columns in the accounts table including sector.

2. Creating Key Measures: Measures like total sales revenue, number of won opportunities, and win rate are vital for our sales performance reporting. We use DAX (Data Analysis Expressions) in Power BI to create these measures directly within our model. This not only speeds up our reports but also keeps calculations standardised across all reports.

3. Defining Dimension tables: Dimension tables such as accounts, product , and sales teams help us slice and dice the data for detailed analysis. Setting these up correctly ensures that we can explore our data from various angles to uncover deeper insights.

A dimension table is a table used in a database to store details about the attributes of something, like the categories, dates, or customer information, to help analyse and understand the main data.

Snapshot of how relationships are formed. All ‘to’ columns are dimension tables.

Best Practices for an Efficient Data Model

  • Keep it simple: Start with essential tables and relationships. Avoid overcomplicating the model which can degrade performance.
  • Use star schema: A star schema layout (with one fact table, sales_pipeline, connected to several dimension tables - accounts, product, sales_teams) often works best for analysis and query performance in Power BI.
  • Optimise DAX calculations: Keep your DAX formulas efficient and straightforward. Complex calculations can slow down your reports significantly.
  • Regularly review and refine: As your data and business needs evolve, so should your data model. Regularly revisit and optimise your model for new requirements and data sources.

Conclusion

A well-thought-out data model is the backbone of effective data analysis in Power BI. By following the steps and best practices we’ve discussed, you can ensure that your model is not only robust but also scalable, and can handle additional data and complexity as your business grows.

Have you built a data model in Power BI before? What challenges did you face, and how did you resolve them? Drop your comments below, and let’s learn together!

Happy Data Modelling !

Next Article: A Comprehensive Overview of Designing a CRM Sales Performance Report for MavenTech in Power BI : Part 4

Articles in Series:

Harnessing CRM Data for Insightful Sales Reporting at MavenTech: Part 1

Mastering Data Cleaning and Transformation with Power Query at MavenTech: Part 2

A Comprehensive Overview of Designing a CRM Sales Performance Report for MavenTech in Power BI : Part 4

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