Separating logistics flows in the Chicago Public School system

The central Chicago Public School warehouse was responsible for the distribution of supplies to 600 schools, including over $10 million annually of engineering and educational supplies. The system was fraught with problems – deliveries were not made according to schedule, schools were hoarding inventories, and some schools were paying a premium for reliable service from third party suppliers. This paper reports how we improved this logistics system. We built a mathematical model of the system, validated our model using historical data, and used the model to evaluate the impact of potential changes to the system. Our recommended changes were implemented throughout the system. We report the impact on system performance. The redesigned system shows a dramatic reduction in lead times, a reduction in capacity requirements, and an overall reduction in system costs.