By Jakob Björklund, Global Director for Process Industries, IFS
24. May 2018 – With real-time machine data on one side With strong business transaction information, manufacturers are increasingly convinced that it makes sense to integrate enterprise software such as Enterprise Resource Planning (ERP) with control systems such as Supervisory Control and Data Acquisition (SCADA). In between, however, are specialized Manufacturing Execution Systems (MES), which often perform the same tasks as these supporting solutions and act as an unnecessary middleman. This article poses the difficult questions of whether MES is necessary in many industrial situations.
Most mid-level and higher-level manufacturing managers understand and value the critical role of Enterprise Resource Planning (ERP) software. At a high level, Manufacturing Execution Systems (MES) – as an intermediate technology between process automation devices in the production hall and ERP software – however, is a much more difficult-to-define process and is therefore reviewed by many manufacturing companies. Here is the reason.
New Learning Required
Common definitions of MES suggest that it tracks and documents the transformation of raw materials into finished products and provides information that helps decision makers understand the real-time conditions in their work. It helps organizations streamline asset processes and control input, human resources, machines, and support services.
The problem is that most of these requirements can be met by modern ERP software. The ERP functionality provides full traceability for input from inventory and non-inventory quality management tools. Human resources are managed through human resources, while support services are handled from outside the organization through embedded contract management tools.
Documents relevant to these various disciplines are processed by native document management functions that enable any document – be it a material review report or a personal training record, to work orders, production orders, sales orders or production recipes to virtually any object in the application On the other hand, the documentation in an MES refers to more detailed transaction logs than to the actual documents handled in an ERP document management.
This provides the core of MES as part of a unified ERP product and not through point-to-point integration.
MES is in the middle
MES serves as a middle layer between ERP and equipment equipped with Programmable Logic Controllers (PLCs), which is a challenge on several fronts. One problem is that other systems that are close to the equipment often already fill that role. In my experience, most industrial settings that would really benefit from MES already have a SCADA system that performs several of the same functions – including the parent process control of automated devices and the collection of real-time data on the operation of devices.
Even though MES is not directly provided by the device manufacturer, it may be more of a consulting and integration project than a defined software solution. The majority of the costs associated with many MES products are in reality services rather than software. In some cases, the device manufacturer may require operators to purchase additional specialized modules to make data accessible to external systems – modules that may again overlap with the common MES platforms. Even though it acts between ERP and the productive level as a middle tier of assets, MES will not necessarily do a better job than any other competing discovery tool, simply because SCADA, MES and other systems speak a completely different language than ERP. MES logs device status in about every millisecond, while ERP typically needs to capture defined data points at the end of each batch or production run.
The information relevant for ERP is a small subset of all the information normally collected in the MES. So while MES collects machine data in a continuous data stream, the ERP collects machine information in the form of inputs, outputs, material transactions and machine times in aggregated form. When it comes to data flowing from MES to ERP, some kind of application will be needed to parse data before it reaches ERP, separating the mass of irrelevant data from the critical few.
ERP: Cut Out Middleman and Retain Control
There are two well-defined methods for monitoring and controlling real-time conditions, either at the plant or through a portfolio of distributed assets and software systems. First, if data points shared between sensed assets and supporting ERP applications are well defined, integrating ERP data directly with dashboards containing key KPIs is relatively easy. Second, When Data Is Captured with IoT-enabled Devices IoT discovery platforms, such as Microsoft Azure, can be combined with Enterprise IoT connectors to process or analyze data before sending it to the ERP solution.
None of these approaches is duplicated with existing plant or factory automation systems. In the few cases where MES is still desirable, operations managers can fall back on industry-specific MES or those available from certain equipment manufacturers. This will help reduce the consulting and professional services component of manufacturing projects while reducing uncertainty or project risks.
About the Author
Jakob Bjorklund is the global director of the process industry at IFS. Bjorklund holds a Master of Industrial Engineering from Linköping University. During his 21 years with IFS, he worked in consulting, sales and marketing as well as product strategy for process manufacturing and supply chain management.