GIVEN-CHINYAMA/zambia-retail-sales-data-warehouse-bi

End-to-end retail data warehouse and BI system for a fictional Zambian retail chain — built with Python, SQLite (star schema), Pandas, SQL analytics, Matplotlib, Seaborn, Plotly, and Power BI. Features 150K synthetic transactions, 7 KPI SQL queries, 8 professional visualizations, and an auto-generated executive report. # 🇿🇲 Zambia Retail Sales Data Warehouse & Business Intelligence System > **End-to-end data engineering and analytics pipeline for a fictional Zambian multi-branch retail chain — ZamRetail Ltd — built entirely in Python, SQL, and Power BI.** --- ## 📌 Project Overview This project simulates a **production-grade retail data warehouse** for *ZamRetail Ltd*, a fictional multi-branch retail chain operating across five Zambian cities — Lusaka, Ndola, Kitwe, Livingstone, and Kabwe. It covers the **complete data engineering and business intelligence pipeline**, from synthetic data generation through to an executive BI report and Power BI dashboard export — demonstrating skills that are directly applicable to real-world data analyst and data engineer roles. > 💡 All data is synthetically generated and does not represent any real business or individual. --- ## 🎯 Business Problem ZamRetail Ltd operates 7 branches across Zambia and generates tens of thousands of transactions monthly. The business needs: - A **centralised data warehouse** to consolidate sales, customer, product, and branch data - **SQL-powered KPI reporting** to track revenue, margins, and growth trends - **Customer segmentation** insights to guide loyalty programme investment - **Branch and product performance** comparisons to inform expansion decisions - A **Power BI dashboard** for executive-level reporting --- ## 🏗️ System Architecture Raw Data Generation (Python + Faker) │ ▼ ┌─────────────────────────────────────┐ │ STAR SCHEMA DATA WAREHOUSE │ │ (SQLite) │ │ │ │ DIM_DATE ──────┐ │ │ DIM_BRANCH ────┤ │ │ DIM_PRODUCT ───┼──► FACT_SALES │ │ DIM_CUSTOMER ──┤ │ │ DIM_EMPLOYEE ──┘ │ └─────────────────────────────────────┘ │ ▼ SQL Analytics (SQLAlchemy) │ ▼ Python EDA + Visualizations (Matplotlib · Seaborn · Plotly) │ ▼ Power BI Export (.xlsx + D …