What is the difference between OEE and MES?
It's common to hear the phrase "we need an MES." Although in some segments this need is real, it's essential to understand exactly what this solution does and whether we are acquiring the right one. Before drawing any conclusions, it is essential to understand that MES (Manufacturing Execution System) and OEE (Overall Equipment Effectiveness) are two distinct solutions used in industry to improve operational efficiency and performance.
MES is a production-control system that manages the execution of manufacturing operations in real time. It is designed to monitor and control manufacturing processes, track raw materials, manage quality, schedule production, and more. By providing real-time visibility into manufacturing operations, MES helps companies optimize processes, improve efficiency, reduce costs, and ensure regulatory compliance.
Its definition has changed significantly over the decades, with layers of management and control added to its scope. If we assess this scope solely under MESA International's framework — the pioneering organization for evaluating this type of system — we'll see that the definition has gone through 4 historical iterations. The broader the scope required as MES, the greater the complexity, the prior data work, and the effort needed in process design and cross-area involvement.
However, even with the ability to manage multiple facets of production execution, many companies inadvertently look for an MES solution to address a central theme in any industrial environment: the productivity of their resources. This is where OEE — and solutions focused on it — come in.
Essentially, OEE is a metric that evaluates the overall effectiveness of equipment on a production line. It considers three main efficiency factors: Availability (time the equipment is available for production), Performance (actual production speed compared with ideal speed), and Quality (percentage of items produced correctly). OEE is used to identify opportunities to improve machine productivity, reduce downtime, increase output, and improve product quality. Implementing a real-time productivity system focused on OEE and highly automated is, in turn, much simpler and faster.
If your goal is to extract maximum productivity from key resources through the three pillars above, monitor production to understand real capacity per product and work center, and identify inefficiencies and their root causes per machine or station, an OEE solution is the most effective choice.
However, if you have very high criticality in equipment-maintenance management, need to improve material traceability beyond what your ERP allows, and/or need a solution with specific, advanced quality-management features, you should look for an MES solution. This solution can be off-the-shelf or even an internal development of those features on top of an existing OEE-centric solution, since the scopes of materials, maintenance, and quality can often be very specific to each company.
In short, the confusion between the two solutions arises from the scope and focus of each, which can lead to mistaken expectations about their features and goals. For example, implementing an MES can improve overall operational efficiency, but it doesn't necessarily guarantee an automatic increase in OEE. Likewise, improving OEE on a specific machine may not solve broader production-management issues that an MES could address.
It is therefore essential to understand the distinctions between MES and OEE and to recognize that each plays a different role in improving operational efficiency and performance in industry. Choosing the right system to meet specific needs and achieve the desired results is essential to business success.
If you're interested in implementing real-time OEE in your plant, learn about Evocon and see how this technology can help!
