MES vs ERP: Breaking Down the Differences

In my 30 years of manufacturing, I've come across many different acronyms for the processes and software systems used within a manufacturing facility. In fact, many of the plants I've gone into have their own handbook of acronyms, such as MES and ERP, that they use each day.

If you want to keep up in meetings, you'd better learn these acronyms quickly.

I've been guilty of just throwing around acronyms and thinking everyone involved knows what they are. And I've also been left in the dust, only to stop and interrupt the synergy of the meeting by asking what they stand for.

But the main acronyms you'll hear in terms of plant support, at least for software, are ERP, MES, LES, MOM, CMMS, MRP, and PLM. ERP and MES are used in almost every manufacturing facility every day, and we're going to dive into the differences between them.

MES vs ERP: What Is an ERP System?

ERP stands for Enterprise Resource Planning. It's somewhat like the brain of your factory. It ties together many of the other business processes within the plant and enables the flow of information between them. It's the financial engine for the facility and includes:

• Accounts payable, receivables, payments, and collections.

• Purchasing of raw components to build the product, including the consumption of the components for the reordering of those parts and tracking the delivery of the product.

• Supply chain management, inventory management, warehousing, and storage locations.

• Managing sales of product orders, including when to build and ship those orders.

• Production planning and Bill of Materials (BOMs) (another common acronym) for production builds.

• Managing human resources for payroll, benefits, and hiring.

ERP software is very good at purchasing, planning, and managing resources within the plant — and paying the bills that keep the lights on. It also stores data and enables reporting on key financial KPIs so management can make decisions on where to improve. While these are the primary functions of an ERP system, you can typically add on other modules, depending on what your ERP provider offers.

MES vs ERP: What Is an MES?

MES stands for Manufacturing Execution System. MES is used to monitor the product being made on the floor through your machines and send the data to other systems and servers for storage. Many companies like to custom-build their MES systems so that they can track production processes in greater detail. The main points you need to know about the function and benefits of an MES are:

• Part traceability and the genealogy of the components that go into making the product. Depending on the type of product you make, you may not need this level of detail. For industries that do require it and will pay for it, traceability and genealogy are essential parts of an MES.

• Recipe management. This functionality sets up the machine controls needed to run the product. An example of this is like going to your microwave and pushing the popcorn button. The microwave has been pre-programmed for the amount of time and heat needed to make a perfect bag of popcorn.

• Machine process controls to monitor any change in the process and store the values for reporting. Changes can be captured using the pressures, flows, torque values, and many other variables to help maintain the quality of the product.

MES and ERP Working Together

These two manufacturing systems have a lot of crossovers between them in how they track the flow of the product through the plant. Most companies need a blend of the two to maximize plant efficiency. They need to be able to talk to each other, collect data, and present information to decision-makers.

I like to compare the many different software systems used in a plant to those of a modern car. A car is made up of various components made by many different manufacturers and then brought together to create the best customer experience possible. You can think of the main body of the car as the people who built the product at the plant. The engine could be an ERP system. Then, the MES is the transmission. Of course, there are many other components of the vehicle, just like there are many other software systems used to maintain the plant. Steering, gas, and brakes could be your Lean Execution System (LES) working in harmony with others to help support and track progress in the plant.

Closing Thoughts on MES vs ERP

Here's the main difference between an ERP and an MES and what each does best:

• ERP is the financial information system for the company.

• MES is focused on the building of the Products that the company produces.

Now, when you're thinking of making a change or even going in a new direction with these systems, make sure you know what you need first. Start small and always use an evolutionary approach. It's always better to start simple than to use the disruptive rip-and-replace strategy, which will usually fail.

Next time you’re in a meeting and you hear discussion about about MES or ERP, you can think, "Hey, I know what that does. It’s like the car’s engine." The financial engine, that is.

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