This document provides an overview of data science and its applications in retail. It discusses how a retail company in Kazakhstan was previously using Excel to determine what and how much to purchase from suppliers, but faced challenges with taking too much time, making mistakes, and difficulty scaling up. A case study is then presented on using data science to help the retail company with inventory planning and management by analyzing past sales history, demand forecasts, stock levels and purchasing parameters to avoid stock outs and optimize purchasing decisions.