What do you really need an MES for?
Thomas Punzenberger, boss of Austrian SCADA vendor Copa-Data, is on record as an MES sceptic. It’s not that he doesn’t think that the functions performed by other vendors’ MES packages aren’t needed; it’s just that he thinks they should be provided by and from within any decent SCADA package. MES-like modules available within Copa-Data’s zenon SCADA package include the Industrial Performance Analyzer and the Industrial Maintenance Manager. That arguably leaves just one function to be provided by what others call MES, namely integration of what might be called ‘Big SCADA’ with the enterprise. And that has now been added to the Copa-Data portfolio in the form of a SAP-certified bidirectional interface that allows the zenon SCADA package to send messages about any type of event to SAP and to receive control commands from the ERP level.
The Copa-Data view of MES is that directly connecting ERP systems to processes and real-time data through the SCADA system results in combined functionality that takes over the tasks that would otherwise have to be performed by MES or other systems. “We asked ourselves, what do you really need an MES for?” said Punzenberger. “Generally, zenon can communicate with any ERP system. SAP already covers a wide range of requirements with its applications, from order management, bill of materials and schedules, to production planning. zenon can fulfill further real-time, process-level important tasks such as traceability, data acquisition, secure user management or maintenance management. So why should our users need to make a separate MES investment?”
Copa-Data claims that the new interface, which is already in operation with leading zenon user BMW, allows SAP applications to interact directly with the process level, functionality which separate MES applications have difficulty providing. zenon takes over commands, such as recipes and other data sequences, from SAP applications, executes them in cooperation with its integrated straton logic engine and reports the results back to SAP. As a result SAP can, for example, monitor stock in real time, with zenon delivering exact data about real resource consumption from the SCADA level. The SAP application can thus base its functionality on real-time stock levels rather than on planned or predicted levels, thereby enabling just-in-time production and precise and effective long-term planning with consequent reductions in work-in-progress and inventory holding. “Our direct connection to the ERP level gives zenon users access to new ways of efficient and effective production planning,” claimed product manager Reinhard Mayr. “Why invest in an intermediate level, incur additional costs for implementation and maintenance and also increase risk of errors from an additional system?”