A Manufacturing Execution System (MES) is a computerized system used in manufacturing to track and document the transformation of raw materials to finished goods. It provides real-time monitoring of multiple elements of the production process, such as inputs, personnel, machines, and support services. MES works as a real-time monitoring system to enable the control of multiple elements of the production process. MES may operate across multiple function areas, such as management of product definitions across the product life-cycle, resource scheduling, order execution and dispatch, production analysis and downtime management for overall equipment effectiveness (OEE), product quality, or materials track and trace. MES creates the "as-built" record, capturing the data, processes, and outcomes of the manufacturing process.

MES software can help manufacturers take advantage of a key trend in the evolution of manufacturing execution systems: customized production. Instead of mass production, a smart factory could move to mass personalization – and meet the demand for less expensive, highly tailored products with speed and affordability. MES helps eliminate human error in manufacturing by providing real-time quality data checks, yield monitoring, automatic enforcement of specifications and business rules, and as-manufactured lot, batch, device, or unit traceability – all resulting in improved product and process quality and higher productivity. MES provides the flexibility to model and change complex processes and enforce them immediately. MES also provides the real-time feedback needed to quickly identify and resolve issues for continuous product and process improvement and optimization of manufacturing processes.

An MES is essential to drive optimal performance in today’s competitive and rapidly changing manufacturing environment. MES can contribute to overall productivity and profitability by making the manufacturing process information-driven. Regulated industries such as pharmaceuticals, food and beverage, medical devices, aeronautics and aerospace, defense, and biotechnology particularly benefit from MES because regulated companies must adhere to strict regulations to ensure traceability compliance. MES maintains an "as-built" or device history record (DHR) for each product unit and batch by collecting data, processes, and outcomes of the manufacturing process for compliance with Title 21 CFR Part 11 and Part 820 of the FDA regulations.