MES versus MOM Terminology Confusion – Manufacturing Execution System or Manufacturing Operations Management

It is 2014 and the MESA (www.mesa.org) organization is wrestling with an important decision. Does it keep using the term MES (Manufacturing Execution System) or move to the term MOM (Manufacturing Operations Management) to describe manufacturing systems? The debate was very active in LinkedIn’s MESA International group forum and also at a recent MESA webcast panel discussion.

Is it time to change the term “MES” to another term just when it is starting to gain recognition and acceptance? Is there any good reason for the change?

First some historical perspective

The terminology timeline shows the introduction of acronyms for manufacturing systems over the last few decades in three major areas: engineering, inventory planning, and production shop floor. We can see in the diagram that just about every 10-12 years, the software industry gets an itch to introduce a new term. These new terms usually signal an evolution in function or footprint for a software category. It has been one of the ways the software industry defines “progress”.

For example, PLM (Product Lifecycle Management), was introduced in 1995 as an evolutionary vision above the definition of PDM (Product Data Management). Software vendors working on solutions for the engineering departments soon jumped to use the term and fulfill that vision. The bar was set high for the PLM vision and vendors and manufacturing companies are still working on fulfilling that vision.

The term ERP (Enterprise Resource Planning) stopped evolving in the mid 90’s. Did that signal a maturity for that category of solutions? There were minor attempts to introduce an ERP 2.0 term around 2007 and 2010 but they didn’t succeed. The term MES (Manufacturing Execution System) has been around since the early 90’s when it was introduced by AMR Research to be the successor of the term CIM (Computer Integrated Manufacturing).

The CIM term was introduced in 1973 by Joseph Harrington and published in his book “Computer Integrated Manufacturing” in 1979. The term gained popularity around 1984. In the CIM wheel published by SME (Society of Manufacturing Engineering) we start seeing functional blocks for CAD Design, Scheduling, Tooling, Production Control, Quality Control, Maintenance, Material, Fault Diagnosis, Material, and Document management. Building blocks that we will later see in the MES definition.

After the MES term was introduced by AMR Research, the MESA organization embraced it and started writing on the subject and educating manufacturing companies on the importance of creating a platform for managing operations at the shop floor. Michael McClellan also published a book in 1997, “Applying Manufacturing Execution Systems” which further defined the term and the functionality scope.

From page 2 of McClellan’s MES book: “MES is the step of integrating all of the activities between the planning layer and the automation layer as components of a proactive integrated on-line system providing a synergistic process that is greater than the sum of the parts.”

With the definition of MES by MESA we moved from “wheels” to “gears”. Note that there are gears in MES for everything you will later find in the MOM definition and more. Also note that McClellan had introduced a layer of Production Planning on top of MES and a layer of Automation Control under MES. The MESA papers also explained that MES would integrate with ERP, Supply Chain Management and Engineering Systems.

Areas of MES include from the following from its inception:

• Resource Allocation and Status
• Operations/Detail Scheduling
• Dispatching Production Units
• Document Control
• Data Collection/Acquisition
• Labor Management
• Quality Management (real-time analysis of measurements, problem identification)
• Process Management (monitoring)
• Maintenance Management
• Product Tracking and Genealogy
• Performance Analysis

It is also important to note that McClellan’s book also referenced several industry leading companies that were doing MES. This was not just an academic wish list. Discrete manufacturing companies were developing these MES applications.

In 2005, companies in process and batch manufacturing working within ISA95 decided to make their own diagrams and moved from “gears” to “oval eggs”.

The ANSI/ISA9-5 Standard for Enterprise-Control System Integration, made some nice clarifications and numbered the layers between machines and enterprise systems. For example, Layer 1 collects data in seconds, Layer 3 in hours, and Layer 4 in days.

However, they decided to rename the MES layer, Layer 3, to Manufacturing Operations Management (MOM) because they liked the word “Management” better than the word “Execution”. It was a naming preference, not a marker for an evolutionary step in manufacturing systems. It did not raise the bar for manufacturing systems; it was thought to be a better name.

You might actually see a few things in MES definitions which you don’t see in the MOM definition. The ISA95 standard was created by people working in the process and batch manufacturing industry where the manufacturing process is very equipment centric. In those industries, the process design is often the entire manufacturing plant or a fixed manufacturing cell with a flow designed to produce a recipe for a batch of product. In contrast, in discrete manufacturing the process design is more work order centric. The process is often designed for flexible manufacturing cells that can manufacture different types of configurations of product units for each work order. This is why there has always been a difference in how to model the different types of manufacturing. A major problem I have with the ISA95 standard is treating Quality as a separate silo. Quality is really part of every process. But I digress… back to discussions of the terms MES and MOM.

On the lighter side

I do think that the ISA95 team members underestimated how much we love acronyms! Because they might have thought twice about introducing the acronym “MOM”.

In this illustration you see an email I received about a week after the LinkedIn discussion had started with the title “MOMs email list”.

At first I thought, wow… I usually get a lot of unsolicited email offering PLM and ERP users email lists but this time it seemed like someone had an email list of MOM users. Sounded interesting so I opened the email to find out they were actually talking about email lists of Moms, Dads, Parents, Gamblers, Golfers, etc. I chuckled and pressed the delete button. This email illustrates a problem with the acronym MOM. Are we really going to ask the next generation to replace their old MOM and look for a new MOM? I find the MOM term a little hard to write about and use seriously in conversation about manufacturing systems.

A reality check

Is it worth it to transition to the term MOM to help align the discrete and process/batch camps? Even when the discrete manufacturing industries have done so much progress on the adoption of MES and establishment of COTS (commercial off the shelf) solutions for MES? Should the process/batch industries embrace MES even when they don’t feel they are “Executing” something? Google searches for “Manufacturing Execution System” were around 160 per month in 2008 and are around 480 per month in 2014. “Manufacturing Operations Management” searches are only at around 110 per month in 2014.

The move to a new term might be a setback for solutions focused at improving manufacturing operations. Two terms do not make it easier for companies to find the solutions they need. Confusion in the marketplace will only benefit the PLM and ERP software vendors that are trying to penetrate the manufacturing systems arena with broad and thin functionality. Perhaps these software giants are behind the move to change terms. Machiavellian tactics? Conspiracy paranoia?

Is there a third alternative?

Some are suggesting that we limit the use of the MOM term to discussions around the ISA95 model, discussions on “business processes” for Operations, and keep the MES term in relation to discussions about IT “systems” that help us support and execute those processes. Of course, that might start debates on how good or bad the ISA95 models are to represent discrete manufacturing processes versus process/batch manufacturing industries. That might be the topic of another article ; )

When MESA changed the “E” in MESA from “Execution” to “Enterprise” they were on to something. In discrete manufacturing, we are now developing manufacturing software for the extended enterprise. Driven by the reality that over half of our products’ subassemblies and components are manufactured by partners and suppliers.

Perhaps instead of focusing on the MES-MOM debate, we should focus on new terms for the future. Maybe change the “E” in MES and define the next generation of “Manufacturing Enterprise Systems” that will support better supplier collaboration and orchestration. Is it time for a four letter acronym? “eMES” for “Extended Manufacturing Enterprise Systems”? Some software vendors are already working on these solutions. It would be nice to have a market definition that supports a broader solution footprint for the broader problems manufacturers are trying to solve today.

Perhaps the term PPM (Production Process Management) or the term Collaborative Production Management (CPM used by ARC Group) will stick. I recommend everyone read the the paper by Michael McClellan titled “Improving Manufacturing Excellence by Managing Production Process across the Value Chain”. It is an example of how we are now looking for tools to manage across the entire value chain.

My vote is to embrace a new term when we are ready to raise the bar for the software category. There is a need to define a new footprint that extends into the supply chain, not at a separate Layer 4, but as an integrated part of the manufacturing process. We should focus as architects of manufacturing systems on this next generation and what we are going to call it. We should look ahead, not back.

References

• “Computer Integrated Manufacturing”, Krieger Pub, Joseph Harrington, 1979.
• “Computer Integrated Manufacturing” by Cheng WU, Yushun Fan, Deyun Xiao, 1999
• “MES Explained – A High Level Vision”, MESA International, 1997
• “Applying Manufacturing Execution Systems” Michael McClellan, CRC Press/APICS, 1997
• ANSI/ISA9-5 “Standard for Enterprise-Control System Integration”, ISA, 2005
• “Improving Manufacturing Excellence by Managing Production Process across the Value Chain”, Michael McClellan, 2012

 

Comments

[Conrad]

The latest trends in MES/MOM software adoption:
http://www.manufacturing-operations-management.com/manufacturing/2017/09/the-roi-payoff-of-manufacturing-operations-management-fuels-new-initiatives.html

[Patrick Mornieux]

Hello,
I liked this discussion and explanation showing the evolution of past concepts and the progression into the maturity of the vision. I agree that MOM is a confusing term less clear than MES. To be more relevant i would have chosen the acronym "MEM" meaning "Manufacturing Execution Management". MES would make the link with the former well known MES but in a larger vision where "System" is replaced by a complete "Management" meaning that all different related topics are embedded.

[Firma clujeana]

Thanks for sharing. It's a little easier to understand, but it's still quite a complex topic.