What is an MES System? Part #1

What is MES System?

Manufacturing Execution Systems (MES) have been available on the market for quite some time now and for buyers at any stage of research, there are literally hundreds of MES options to consider.  As the term “MES” tends to cover a very broad range of capabilities, it’s unlikely to find any two solutions that will offer the exact scope of functionality. This is especially true within just the last few years, given the rapid progress of digital technologies related to “Smart Factory” or “Industrial Internet of Things” (IIOT) initiatives. It’s therefore crucial for you to understand the basic principles behind MES so that it can be put to work for your organization’s requirements, instead of the other way around.

In this three-part blog series, we’ll break down the fundamentals concepts of MES so that regardless of where you’re at with your research, you’ll be equipped with some new tips and principles to incorporate into your knowledge base. You can also download the full whitepaper, “Basic of MES” here.

The Best Approach to MES Systems

It’s been shown that the best approach to MES is to first determine the key business goals that you’d like to achieve, and then work backwards. This avoids endlessly wading through technical specs that describe a myriad of functionalities and can appear confusing until their exact context within the projectis clarified.

In reality, some MES features and functions may be irrelevant for your immediate specific need, so this helps you take the guesswork out of the selection process. Of course these considerations will need to be noted for any potential future phases but we’ll get to that later.

Your goal in selecting an MES software (and the supporting hardware technologies) should be to create a plan towards a single platform that will meet your longer-term targeted objectives without any need for eventual replacement. The price of an MES system shouldn’t be calculated as simply the cost of the software and hardware, but rather the investment in the changes that a factory operation driven by MES will make, in order to allow the MES system to work effectively. Different MES systems will prescribe their own “best practices,” and the fundamentals of these practices should be compared to both your current and targeted operation. In most cases, the cost of change and the cost of ownership can be greater than the capital purchase itself.

MES & ERP Together

Once implemented at your facility, MES will work together with the other existing and future factory control systems. Most factories have an Enterprise Resource Planning (ERP) platform in place, which usually will appear to have some overlapping functionality with MES.  ERP however, is by no means an equivalent for MES, as it’s typically meant for logical planning for the factory, rather than handling the day-to-day physical operations that MES is designed for. An ERP system on its own doesn’t not have enough knowledge about individual manufacturing processes and capabilities, which creates the need for an intermediate process to “translate” the ERP data into something that can be executed; without MES, this is often done manually, which takes valuable time and resources.

With MES, information from ERP about requirements is gathered and used to build specific production operations that the MES platform will then manage. MES next provides highly-accurate and detailed, real time information about operations back to ERP, and this historical information can be queried and used to enhance the your planning capabilities for the next time around.

The powerful relationship between MES and ERP should be a key factor for consideration, especially, the point of exchange between the two systems. The simplest way to approach this area is to define and measure the roles of the two systems based on their strengths. In many factories, the planning is handled in a simple, logical way by ERP, while the more complex physical tasks that must take place in production are managed best by MES in a live and detailed environment.

Starting Out – The Value of MES Systems

When considering MES, your starting point should the endpoint of production, the completion of products that are ready for shipping. From the customer perspective, the most important metric here is on-time delivery. For the manufacturer, it’s the cost of building product as well as the capacity of the facility. Capacity here is defined and dictated not just by the range of equipment in place, but also how it’s used and managed when that inevitable time comes to change from one product model to another. When making a high mix of products, the flexibility of both your manual and automated production operations will dictate the overall effectiveness of your facility.

If you’re producing many different product types simultaneously, determining your overall capability to meet delivery goals can be a very difficult calculation. Here is the first real potential value of MES. Access to a computer-based digital factory model creates visibility into the status and performance of your processes at all times, and this presents countless opportunities for improvement in the flow of shop floor production and the assignment of work-orders. A cornerstone of MES is the live-time tracking of final products and sub-assemblies. Each production unit can be tracked on its journey through the factory with a unique ID with a label or an etched barcode.

The Benefits of A Simple MES Operation

At each key station, the unique ID of each production unit will be read, and this provides several key related values. First, MES processes information about each event, in this case showing the exact location of every production unit. Then, using the timings of each reading, MES will present a visualization of the flow of production units via graphs that show “Key Performance Indicators” (KPIs) that help both Production Management and Engineering understand the performance. For example, you’ll be able to identify “bottleneck processes” where products are queuing prior to a workstation. You can also find indications of “starvation of operations”, or situations where operators are idle as they wait for the next production unit to arrive. MES will display production units that fail test or inspection processes and need re-routing to repair stations as well as any disruptions that this is causing to the main production flow. Details about efficiency, productivity, Overall Equipment Efficiency (OEE) and more can all be determined by analyzing the throughput of production units through each production process and the travel time in between them.

Tracking production units like this leads to subsequent benefits. MES can ensure that when the ID of each product is read, conformance against the work-order is checked, so that each production unit will only go through each process in the proper sequence, including any repair loops. This enforces that none of your production processes, or more crucially, any test or inspection operations, are missed. Linking your MES systems with your engineering data preparation systems can also ensure that the appropriate operation standard and setup documentation for the operators will exactly match the product being manufactured, including any material substitutions or revision variations.

The ability to provide electronic documentation eliminates several risks that are often associated with paper-based document management, especially in the event of an audit situation, where regulatory compliance is key and revision control is EVERYTHING. Data from production processes, such as a test result, can also be collected and attributed to each production unit, creating an entire history of production in the form of production unit traceability. The level of complexity of this traceability will depend on how much data can be acquired from your factory’s machines and how much time is available for manual input from your operators.

A critical factor in the success of any new MES installation is machine connectivity and the quality of the system’s user-interfaces. Some clear differentiators of MES product capability are the ability to pull and interpret data from various different types of machines and the ability to consistently gather manual operator input in a controlled manner. MES interfaces are personal to the operator, and don’t need to be fixed to any operational location. Often there will be physical processes dedicated to certain products, such as with functional tests, so not all processes will need to be simultaneously manned.

This simple look from a “top level” of MES provides a fundamental visibility into the operation and valuable details about how it’s working, while also highlighting the areas where improvements can be made. However, there are many underlying factors that you need to consider to determine how you should approach any changes, and what corresponding effects those changes may have. Production has significant dependencies on other aspects of the overall factory operations as well. These dependencies include quality management, material preparation and logistics, engineering data preparation, and management of key tools and resources, including people.

The scope of MES spans deeper into the areas of factory management that include support for these dependent processes, so that you can address the root causes of any symptoms you see in the production flow, and optimize and improve the dependent processes themselves. In the next part of this three-part “What is MES?” blog series, we’ll break down how MES systems handle factory dependencies and internal supply-chain management. Click here to download the full whitepaper, “Basic of MES”.