Manufacturing execution systems and ERP integration: A happy manufacturing marriage?

It used to be what happened on the plant floor stayed on the plant floor.
The manufacturing execution system (MES) -- a central system for managing all manufacturing information such as resource allocation, manufacturing planning, supply chain information and quality inspection numbers -- operated as an isolated and self-contained system.
Similarly, the enterprise resource planning (ERP) system, which pulls together and stores business operating information about human resources, accounting, customer relationship management and other financials, hummed along independently. Both systems have always been critical to the manufacturing organization, but until recently, had never been linked.