What is an MES?
An aspirational view from the factory floor (Part 1/5)

What is an MES? That’s a good question, but a better question to start with is, what does MES stand for? MES stands for Manufacturing Execution System, but hang on, that’s just what I call it. Some people call it a Manufacturing Operations Management System, or MOM. Others call it a Computer Integrated Manufacturing System, or CIM, and yet others call it a Manufacturing Management System, or MMS.

Confusing? Yeah, a bit. Whatever you call it, though, just don’t call it a MESS, because, well, none of us wants a mess inside our factory. Okay, so what is an MES? In this five-part series, we’ll take an aspirational look at what the MES is all about.

To begin, we’ll need to go back to first principles. At the highest level, the purpose of an MES is to facilitate the movement of product through manufacturing. More specifically to define, direct, and document a factory’s activities. First, we need to plan the work of the factory.

What is it that needs to be done and when? How specifically does it need to be done? And what resources are needed along the way, like equipment or parts or chemicals? This is the configuration process for the MES, defining all the resources, materials, and processes needed to build whatever it is the factory is building. Next, we need to direct the work of the factory to ensure that the right thing is done at the right time, and the right resources are used in the process. And we also need to document exactly what’s been done along the way. Among other things, this ensures everyone is on the same page about the work that has already been done to the things we’re building in the factory.

We definitely don’t want to mistakenly do the same work twice, nor do we want to inadvertently skip a necessary step. After manufacturing is finished, we need to show that the right work was done at the right time. Being able to show complete processing history is important not only for the internal quality verification, but it’s also important for external standards certification and often required by customers to meet their own regulatory requirements.

 As it turns out, much of the functionality of the MES is driven by key requirements of the ISO 9001 quality management standard. Three of the fundamental concepts of ISO 9001 are to say what you’re going to do, do what you said you’d do, and show that you did what you said you do. The major objectives of the MES align clearly with these concepts.

But some would say that’s not enough. It takes a lot of effort to configure an MES with all those process definitions. And it takes even more to consistently and accurately document the work that’s been done throughout the manufacturing process for everything the factory is building.

And that’s a continuous effort not just a one-time configuration. An MES requires a lot of effort and manufacturers want to get more out of it than just a certificate to hang on the wall to show they’ve complied with the ISO 9001 standard. That’s just not enough.

Manufacturers want an MES that helps move their business forward. They want a system that helps them answer business questions like do we have enough capacity for a big new customer? Or can we reduce manufacturing time to prevent losing an existing customer whose orders have been consistently late? Or are we on track to hit our production targets for the quarter? They want a system that answers operational questions like what lot should be processed next? Which is a surprisingly difficult question to answer. Or will the customer’s order be finished on time? Or what are our options to improve cycle time? And they want a system that gives clues to answer process-related questions like, is the process stable? Or what can we do to improve yield? Or where are all the defects coming from? Manufacturers want to use the data generated by their MES for two simple purposes.

To provide actionable insights that speed business impacting decisions. And to provide advance warning of problems that lay ahead, preferably so they can be addressed before they become problems. In short, the job of the MES isn’t just procedural to define and track manufacturing processing.

It’s also about the data that’s generated and how that data can be used to drive continuous improvement within the factory, as well as bottom line results. As we talk about the capabilities of an MES, the important takeaway is less about what those capabilities are and more about why they’re needed and how they help solve problems in manufacturing. From a high-level perspective, there are three basic pieces to an MES.

Process definition is where all the configurations happen, where the work of the factory is planned in advance. You could call lot tracking the runtime of the MES, where process definitions are used to ensure the right processing occurs at the right time using the right resources. And everything that happens is documented along the way.

Reporting takes the data that’s generated in lot tracking and organizes it, presenting it in a form that provides actionable insights about different aspects of factory performance. Analytics democratizes access to lot tracking data, allowing end users to slice and dice data according to their own needs and create new insights in a fraction of the time it would take to request a custom report. In part two, we’ll take a look at process definitions within the MES, where the work of the factory is planned in advance in exhaustive detail.