Manufacturing Execution Systems [MES]

Introduction to Manufacturing Execution Systems [MES]

In the world of manufacturing and industrial automation, we often talk about different “layers” when it comes to control systems. These layers are based on a pyramid approach derived from how these elements generally interact with each other. It’s important to note that although we still use and teach this representation, the data flow isn’t linear between these segments. These layers are as follows:

• Layer 1 - Field Devices | Sensors, Motors, Valves, Actuators, etc.
• Layer 2 - Control Systems | PLCs, HMIs
• Layer 3 - Visualization and Data | SCADA Systems
• Layer 4 - Manufacturing Intelligence | MES
• Layer 5 - Business Intelligence | ERP

What is a Manufacturing Execution System (MES)?

As you can immediately tell, the MES layer lives between the SCADA and ERP layers. The MES provides insights that are specific to the manufacturing process but aren’t fully tied to the business as a whole. In the real world, here’s where these nuances lie: 

The SCADA will collect, store, and report raw data - it will collect temperatures, levels, faults, and machine status. It will present this information to the operator in the form of charts, indicators, lists, etc. It will provide visuals as to what happened in the process, the setpoints that have been used, and the current status of the operation.

The MES will synthesize the information coming from the plant floor, pull in data from the ERP, create various reports, and push some of the information to key executives and / or back to the ERP. The synthesis varies by application. For smaller facilities, the MES will provide OEE type of metrics - How well is the facility running? How good did the last shift run? Have we met our quota? For larger facilities, the MES will provide data on which breakdowns to focus on - How many stops did a specific machine have? What was the nature of those stops? Where has a batch process failed last week? Where did we miss an opportunity in terms of ingredients?

The ERP layer is responsible for business intelligence. It can process everything from what’s happening on the plant floor to accounting, payroll, HR, etc. The ERP is a layer that is not unique to manufacturing; you’ll see an ERP system in most businesses regardless of their vertical - retail store, e-commerce platform, software application, etc. The MES is specific to manufacturing.

What is the difference between MES and ERP?

As mentioned above, there are a few key differences between MES and ERP. The MES is unique to the manufacturing industry and is focused on manufacturing-specific KPIs. The MES is typically tied to the plant floor and data that comes from the PLCs, HMIs, and SCADA systems, while the ERP mainly ingests data from the business systems. It’s important to note that the lines are blurring as tools that combine the two are becoming more readily available.

The other main difference between MES and ERP is the users. Depending on the business, an ERP will be utilized by most executives to get a pulse on the business while the MES is primarily built for those on the manufacturing side. As mentioned above, the MES will ingest some of the ERP elements to aid in providing manufacturing data, but it’s not going to be concerned with nearly as many aspects of the business as the ERP systems. It thus will only access the applications it needs to evaluate the manufacturing aspects.

What is the difference between MES and SCADA?

SCADA systems are deployed in most manufacturing facilities to monitor and control manufacturing assets. A SCADA is typically going to control multiple machines, lines, or areas of a production facility. The difference between an MES and a SCADA is that the MES isn’t going to perform control level functions. The MES is primarily concerned with analyzing the performance of the system by using various data coming from the SCADA, or production equipment directly (PLCs, HMIs, etc.). Furthermore, the audiences of the two are different - SCADA systems are used by those that run the facility, while MES applications are predominantly aimed at executives and managers looking to decide how to better the operations, when to schedule certain runs, where to allocate budget, etc.

Key Elements of Manufacturing Execution Systems [MES]

Depending on the facility, industry, size of the company, team effectiveness, and region, you’re going to find different flavors of MES. As discussed above, there’s no set of standards which dictate what your facility should or shouldn’t implement; it’s on a need basis.

So what are the common features of an MES?

MES for Operations

What does the operations department of a manufacturing plant concerned with? They need to run production, maintain uptime on their equipment, schedule batches, etc.

The MES can help with all those functions:

• Understanding equipment uptime | One of the ways the MES will provide information about uptime is through OEE (Overall Equipment Effectiveness) which provides the metrics for every discrete machine on the plant floor.
• Running production | MES will provide data on the historical performance of a batching, packaging, or converting process.
• Scheduling | The MES typically allows the users / operators to schedule different runs on specific lines based on SKU, performance, availability, etc.

MES for Maintenance

Maintenance is a critical component for manufacturing facilities. There have been specific tools developed for maintenance activities in manufacturing; with one of the main ones labeled CMMS (Computerized Maintenance Management System). These systems allow for managing work orders, scheduling required downtime, predicting when downtime will be necessary, tracking parts required for maintenance, scheduling maintenance shifts, and much more. The MES will tie in production data and a lot of these maintenance components as part of the offering.

MES for Leadership & Alignment

Your facility should have regular alignment meetings which can be held on a daily, weekly, monthly, and / or yearly basis. During this meeting, the involved teams should be reviewing the data created by the MES and aligning on the tasks to be completed. On the daily, the teams should review what happened in the previous shift / run and prioritize smaller tasks to address, schedule downtime if maintenance is required, etc. On a weekly basis, you can figure out if certain teams / shifts are running better, understand the discrepancies between different batches / production runs (if any) and complete bigger maintenance tasks. On a monthly / yearly basis, you can review how well your equipment is performing, understand where to allocate business ressources based on your strategy, and figure out what the focus of your teams should be.

Reasons to Implement a Manufacturing Execution System [MES]

I’ve had many conversations with customers and end-users that quite frankly didn’t need a dedicated MES application. They’ve been sold by a vendor, or consultant that they absolutely must be able to track and analyze the data they have which will in turn lead to significant ROI. For certain facilities it simply isn’t the case. Let’s explore a few topics around this:

SCADA <> MES <> ERP Convergence

Regardless what your opinion is on the three upper layers of the stack (SCADA, MES, ERP), there’s always some overlap. In other words, certain components of the MES will be found in SCADA systems and ERP systems. The reality is that if you have a solid foundation via a SCADA platform, you can most likely get a lot of the information you may need / want there. Similarly, if your business is struggling with certain business functions, it’s possible that you’ll get your answers in your existing ERP solution, or by investing there before deploying something else.

I’d urge you, before seeking to deploy a new tool / system to speak with an individual that knows your systems well enough, understands the problems you’re looking to solve, and has relationships with vendors that have installed your system.

The IT / OT Convergence Debacle

MES components will most often be governed by the IT while everything below (SCADA, PLCs, HMIs,) is going to be handled by OT. As you begin to ingest data into an MES level application, you’re guaranteed to become victim of multiple debates around who owns the project, who’s going to do the work, who’s going to maintain the system, who’s going to handle networking, etc. All of these questions can be answered, but remember that this means that it will take effort, time, and money. The alternative would be to, as mentioned in the previous point, seek out ways to get the data from one of the existing systems that don’t necessarily bridge the two - SCADA (OT) and ERP (IT).

Getting Answers to Production Questions

I’ve walked onto multiple plants and asked basic questions such as “Why didn’t you meet quota last week?” only to be left with blank stares - there was no tracking of any kind. I’d ask about their different shifts / teams and their performance - once again, there was no tracking to give me that data.

Personally, I have a hard time making recommendations without concrete data - your doctor would never prescribe an aspiring until he / she runs some tests. The same should be applied to manufacturing - how can we create a plan without understanding the performance of our system and / or teams first?

If you’re in a plant management position and you’re seeking out data / answers to your questions without success, perhaps it’s time to look into an MES type of application. Remember that these can address various functions for different departments within a facility - Operations, Maintenance, Engineering, Quality, Sanitation, etc.

Technical Implementation of Manufacturing Execution Systems [MES]

Let’s explore what you’d expect from a technical standpoint when deploying an MES. As mentioned above, the MES will ingest plant floor data, as well as ERP data - what does that mean exactly?

Edge Devices / Industrial Programmable Computers [IPCs]

MES requires an interface to the OT devices - As mentioned above, these are typically SCADA systems, PLCs, and HMIs. However, it can also be a direct connection to the field devices - sensors, drives, VFDs, load-cells, etc. There are a few approaches to getting this data to the MES. SCADA platforms will typically run on an on-prem server. As far as I’m concerned, there’s no SCADAs running in the cloud, but that’s an entirely different conversation…

So, what does it take to get data from PLCs, HMIs, and field devices?

In general, these systems are flexible enough to accommodate different protocols. However, as many know, industrial automation is an amalgamation of dozens of different protocols, which means that you’ll need ways to convert from whatever is in the field to what your MES can ingest. The bottom line is that the typical approach is to manage data using an application that can be deployed on a server or an IPC. This application would interface the devices and funnel the data to the MES.

What is an Edge Device or IPC?

Basically, they’re Windows, Linux, or different OS computers running software. They can run from a very basic converter application to fairly complex MES tools. It really depends on the use case.

Running MES Software

The MES connects to the plant floor but doesn’t need to run on a PC within an industrial cabinet. Typically, you’ll see on-site server rooms at manufacturing sites that host the MES applications. This is done for a few reasons - 1. Non-industrialized IT hardware is typically cheaper. 2. The hardware will generally be accessed via remote connections, connected to many devices, and thus lend itself better to a centralized location. 3. The IT departments typically run other software for the facility on the on-prem servers, so there’s usually some room to either host the application on existing hardware or do so with minimal upgrades.

On-Prem vs Cloud Deployments

This conversation will inevitably be brought up - should we run the MES software on-prem or on a cloud provider (AWS, GCP, Azure, Digital Ocean, etc.)?

There’s no simple answer. I’ve always advised my customers to look at both options. Do you currently support on-prem hardware? Do you have engineering teams capable of managing on-prem or cloud architectures? Do you have a reason to adopt the cloud beyond deploying the MES? What’s the nature of your industry (healthcare, medical devices, government, etc. are notoriously difficult to sell on cloud)?

From what I’ve seen in the industry, I typically advise customers to go the on-prem route unless they can clearly demonstrate the capability and advantage of going to the cloud. Most MES applications can run in either configuration, but there’s more to passing data, building out a robust architecture, and being able to benefit from other services when deploying in cloud environments.

Which MES Software to Choose

There’s no shortage of options when it comes to building out an MES solution. What should you choose for your facility?

The answer, just as above - it depends…

I believe that a thorough analysis of the current architecture and needs must take place before making the call on which platform to use. There’s something to be said about the compatibility of your control system and your MES. In other words, if you’ve got a strong relationship with Rockwell Automation (if you’re based in the US) or Siemens (if you’re based in the EU) it’s likely that you can integrate their offerings much easier than any other platform.

That being said, if you’re looking for a 3rd party MES, there are excellent options as well. From very simple tools (Ex - Peakboard) to full-featured solutions (Ex - Inductive Automation’s Ignition), you can find whatever suits your needs. Understand that depending on what you’re looking to do, you’ll be evaluating different features, different price points, different timelines, and different partners when it comes to integrating these systems into a facility.

Conclusion on Manufacturing Execution Systems [MES]

In conclusion, here’s my take:

From experience, every facility has some sort of MES functionality, weather they know it or not - they’re collecting some data, making decisions, etc.

Most facilities don’t take advantage of the features of their current technologies / tools. This happens due to a number of reasons - turnover, lack of training, lack of information / documentation, etc.

Most MES initiatives need to start with an assessment to understand what’s currently in place and where the business would like to go. Make no mistake: technology vendors aren’t always versed in your operation; they need to fully understand the intricacies of your control systems, processes, and capabilities.

Don’t confuse MES with SCADA and ERP. They have overlapping functionality, but there are differences… We’ve outlined them above.

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