Problem
Retail teams needed a concise view of what drives revenue by product, month, and market. Raw tables made it hard to compare patterns across time and countries.
Solution
I built a Power BI model with DAX for % of total, ranks, and AOV. The report highlights KPIs, top products, monthly sales trends, and a countries view for quick geographic comparisons.
Impact
The dashboard surfaced peak months (Nov/Dec), product concentration, and country contribution mix. Stakeholders could prioritize catalog and markets based on clear trends.
Role & Context
Solo project done in ~1 week using Excel + Power Query + DAX. Built for practice with retail data and reviewed with peers for clarity.
DATA MODELING
- Model Type: Flat, single-table model for performance and simplicity
- Relationships: Single fact table (Year 2010–2011)
- Calculated Columns: YearOnly (extracted from InvoiceDate)
- Hierarchies: Year > Quarter > Month > Day for time-based filtering
DAX CALCULATIONS
The dashboard includes several advanced DAX calculations for comprehensive analysis:
- % of Total Sales: Calculates each product's share of total revenue
- Product Sales Rank: Ranks products by revenue
- Average Order Value: Average revenue per order
- Avg Quantity per Order: Average items per order
- YearOnly: Extracted year for filtering capabilities
DASHBOARD DESIGN
The dashboard follows best practices for visualization and user experience:
- KPI Summary Row: Total Sales, Customers, Invoices at the top
- Main Charts: Bar charts for top products, area charts for monthly sales, map visuals for geographic sales, line charts for customer trends
- Slicer Panel: Year and month filters for dynamic filtering
- Interactivity: Tooltips, cross-filtering, dynamic slicers
- Design: Dark theme for high contrast, minimal clutter, consistent color scheme
RESULTS AND INSIGHTS
- Top-selling product: DOTCOM POSTAGE (0.02% of total revenue)
- Peak sales months: November and December showing significant seasonal increases
- Largest market: Canada identified as the primary geographic market
- Seasonal trends: Q4 showing significant sales increases
- Customer behavior: Clear patterns in purchase frequency and order values
SKILLS DEMONSTRATED
Data Cleaning
Data Preparation
Data Modeling
DAX Calculations
Visual Design
Conditional Formatting
Interactive Dashboards
Power Query
Excel
TECHNOLOGIES USED
Power BI
DAX
Power Query
Microsoft Excel
Data Visualization
CHALLENGES & SOLUTIONS
Challenge: Handling large datasets efficiently in Power BI with performance constraints
Solution: Optimized data model using a flat table structure and efficient DAX calculations, ensuring fast query performance even with substantial data volumes.
Challenge: Creating meaningful DAX calculations for complex business metrics
Solution: Developed calculated measures using DAX functions like CALCULATE, FILTER, and RANKX to accurately compute percentages, rankings, and averages.
Challenge: Presenting multiple insights in a single dashboard without clutter
Solution: Used a clean dark theme with consistent color schemes, organized KPIs at the top, and implemented interactive filtering to allow users to explore data without overwhelming visuals.