Supermarket Price Optimization Dashboard
Leveraged Power BI to analyze multi-store pricing data, identifying a 5.16% savings strategy on monthly household spending.
- Microsoft Excel
- Microsoft PowerBi
- DAX
- Data Modeling
At a Glance
- Identified KSh 743 (5.2%) potential savings from a KSh 14,408 grocery bill by optimizing store selection.
- Recommended mix-and-match purchasing with focus on 5 key items driving 78% of savings.
- Built an interactive Power BI dashboard to compare store and product-level costs.
Dashboard
Business Problem
Like most people, I do a big monthly shop for household essentials. My budget is tight, and I’ve noticed my bill creeping up. I usually just shop at the nearest supermarket (Naivas) out of habit, but I also have Quickmart and Carrefour nearby. I realized I might be overpaying simply by not comparing prices.
My goal was to use my own shopping list data to answer:
“Which supermarket, or combination of supermarkets, will give me the lowest total bill for my exact monthly needs?”
Approach & Analysis
Step 1: Data Collection
Extracted item-level prices from the online stores of Naivas, Quickmart, and Carrefour.
Compiled data in Excel with columns: Supermarket, Product Details, Product, Product Type (Food / Cleaning / Toiletries), Quantity, Cost/Pkt, Total Cost.
Step 2: Data Preparation in Power BI
Imported dataset into Power BI.
Cleaned for consistency: corrected data types, spelling, and capitalization.
Step 3: Modeling & DAX Measures
Built measures to calculate total spend by supermarket and potential savings:
- Total Bill = SUMX(Quantity × Cost/Pkt)
- Naivas Bill / Quickmart Bill / Carrefour Bill = CALCULATE([Total Bill], filter by supermarket)
- Optimal Mix Total = SUMX per product of [Min Product Cost]
- Potential Savings = [Naivas Bill] – [Optimal Mix Total]
- Potential Savings % = DIVIDE([Potential Savings],[Naivas Bill],0)
- Cheapest Store helper logic to dynamically return the best price source per product.
Step 4: Visualization & Insights
Designed a Power BI dashboard with:
- KPI Cards: Bills per supermarket, Optimal Mix Total, Potential Savings (Amount and %).
- Pie Chart: “Where my money goes” (optimized basket).
- Stacked Bar Chart: Supermarket performance by product type.
- Bar Chart: Top 5 “biggest win” items with the highest price gaps.
- Table: Recommended shopping list → Product | Min Cost | Cheapest Store | Product Type.
- Text Box: Actionable recommendations.
Key Findings
- If I buy everything at Naivas (my usual habit), I pay KSh. 14,408.
- Switching entirely to the cheapest single supermarket (Carrefour) saves Ksh. 470 (3.3%).
- Mixing and matching products across stores saves KSh. 743 (5.16%) compared to Naivas.
- Top 5 items alone account for 77.65% of total savings.
Recommendations for an Optimal Shopping Strategy
- Prioritize Carrefour for single-store shopping. It offers a modest 3.3% savings over Naivas without needing to shop around.
- Adopt a mixed-store approach for maximum savings. Combining stores reduces the total bill by 5.16%, the best overall result.
- Focus on just the top 5 high-impact items. Switching stores for these products alone captures 77.65% of all potential savings, minimizing effort while keeping most of the benefit.
- Track supermarket price trends regularly. Small changes could shift which store is cheapest over time.
- Use this analysis to build an automated shopping list, ensuring the strategy stays updated without manual rework.
