A manufacturing execution system (MES) is a software solution that monitors and controls production in real-time. It connects, monitors, and controls complex manufacturing systems and provides manufacturers with the information they need to make better decisions and improve their operations.

Key features of MES include real-time data collection, production scheduling and tracking, quality management, inventory control, and integration with other systems like ERP and SCADA. 

MES improves production efficiency by optimizing scheduling, reducing downtime, minimizing waste, and improving quality control. Real-time data and insights help manufacturers identify and address bottlenecks, streamline workflows, and make better decisions to enhance overall productivity. 

While ERP manages broader business processes, MES focuses on real-time shop floor control. They integrate to provide a unified view of manufacturing operations. MES feeds production data to ERP for improved visibility and decision-making, leading to increased efficiency, reduced costs, and better compliance.

The production planning hierarchy consists of ERP at the top, followed by MES, and then Factory Automation (FA) equipment at the bottom. The FA layer, with its sensors and PLCs, provides the crucial data that MES needs to function while MES executes the plans developed by ERP.

Recently, ERP, MES, and FA vertical integration have been increasingly in demand to achieve end-to-end visibility and control across the manufacturing process. This integration enables real-time data exchange, improved decision-making, and optimized production efficiency. It also facilitates better collaboration between departments and reduces errors.

However, MES is not a silver bullet. The power of MES comes from the link between the information it holds and the workflows it drives. o2Oh is developing a system to make this connection seamless, leveraging both practical experience and advanced technology.