MES Core Functions
The manufacturing planning layer and the control layer descriptions show there is very little relationship between them. The planning system works in hours, days, or weeks and is usually not on-line and available for change or inquiry. At the same time, the device control layer works in microseconds and is generally internal to and part of the functionality of the device, such as a machine tool. The MES fits between these two layers, on-line and able to communicate with the planning system and the device control systems.