MES stands for Manufacturing Execution Systems it is the Digital Transformation of Manufacturing Operations. The definition of MES according to the Instrumentation, Systems, and Automation Society (ISA) is: The MES layer focus in a group of activities (operations, inventory, quality and maintenance activities)

Wonderware MES Software/Operations is an out-of-the-box, configurable, modular Manufacturing Execution System (MES) that manages, tracks, and optimizes manufacturing production processes. It collects production data, executes work orders on the shop floor, and provides production visibility for reporting and analysis.

Wonderware MES software is completely scalable and configurable which helps customers track the transformation of products from raw materials through finished goods.

Wonderware MES can provide below functionality

• Production and Inventory Operations Management (MES Operations)
• Performance Management (MES Performance)
• Quality Operations Management (MES Quality)
• Enterprise Integration

Manufacturing Execution Systems provides a critical link to fill the gap between Enterprise Resource Planning (ERP) and process machinery.

MES is corresponding to Level 3 in the Functional Hierarchy model. This is illustrated in the following diagram: