MES is an information technology system that manages manufacturing operations in factories
Over the years, international standards and models (ISA 95 and B2MML) have refined the scope of such systems in terms of activities, which typically include:
Management of product definitions
This may include storage, version control (Lot) and exchange with other systems of master data like product production rules, bill of material, bill of resources, process set points and recipe data all focused on defining how to make a product.
Management of resources
This may include registration, exchange and analysis of resource information, aiming to prepare and execute production orders with resources of the right capabilities and availability.
Scheduling (production processes)
These activities determine the production schedule as a collection of work orders to meet the production requirements, typically received from ERP making optimal use of local resources.
Dispatching production orders
Depending on the type of production processes this may include further distribution of batches, runs and work orders, issuing these to work centers and adjustment to unanticipated conditions.
Execution of production orders
Although actual execution is done by Process control systems, an MES may perform checks on resources and inform other systems about the progress of production processes.
Collection of production data
This includes collection, storage and exchange of process data, equipment status, material lot information and production logs in either a data historian or relational database.
Production performance analysis
Create useful information out of the raw collected data about the current status of production, like Work In Progress (WIP) overviews, and the production performance of the past period like the Overall Equipment Effectiveness or any other Key Performance Indicator.
Production track and trace
Registration and retrieval of related information in order to present a complete history of lots, orders or equipment (particularly to comply with legal regulation).