D'Addario produces musical instrument strings at its plant in Farmingdale, New York. It produces around 700,000 strings per day across hundreds of stock keeping units for guitars and other instruments. To manage such complex production and inventory, D'Addario implemented lean manufacturing principles including analyzing demand patterns, reorganizing production into parallel cells by instrument type, and emphasizing continuous quality improvement and information flow. These changes reduced uncontrolled inventory levels while maintaining the ability to fulfill most orders within the same day. As a result, D'Addario saw increased profitability and growth following the implementation of lean manufacturing at its string plant.