The functioning of mes systems. MES functions

MES is an information and communication system for the production environment of an enterprise.

Lecture 6. Executive production systems MES

MES is an automated production management system for an enterprise. Tasks and functions of MES. Application area.

The MES (Manufacturing Execution System) is a production management system that connects all business processes of an enterprise with production processes, promptly delivers objective and detailed information to management. In addition, the MES system analyzes and determines the most effective solution to the problem - for example, for a specific manager, such a solution may be a transition to other sources of raw materials, the introduction of automation systems at certain points in the technological process, a change in the delivery schedule, or a reduction in manual labor.

According to APICS (American Production and Inventory Control Society), MES is an information and communication system for the production environment of an enterprise. A more detailed definition is adopted in the non-profit association MESA (Manufacturing Enterprise Solutions Association), which unites manufacturers and consultants-implementers of MES systems:

MES is an automated system for managing the production activities of an enterprise, which in real time: plans, optimizes, controls, documents production processes from the beginning of ordering to the release of finished products. [ 1 ]

MES systems are defined as a collection of software functions that are distinct from those of enterprise resource planning (ERP), computer-aided design and programming (CAD / CAM), and automated process control systems (APCS). The MESA has identified 11 main MES functions:

1. Condition Monitoring and Resource Allocation (RAS). Within the framework of this function, the management of production resources (machines, tools, work methods, materials) and other objects is provided, for example, documents on the procedure for performing each production operation. The correctness of the configuration of the equipment in the production process, as well as its condition, is monitored in real time.

2. Operational Detailed Planning (ODS). This function provides prompt and detailed work planning based on the characteristics and properties of a particular product, and also calculates in detail and optimally the load of equipment during a particular shift.

3. Production dispatching unit (DPU).Provides ongoing monitoring and scheduling of the production process, tracking the execution of operations, the employment of equipment and people, the execution of orders, volumes, batches and controls in real time the execution of work in accordance with the plan; allows you to track all ongoing changes in real time and make adjustments to the shop floor plan.

4. Document Management (DOC). Provides the passage of documents that must accompany the manufactured product, including instructions and standards of work, drawings, part programs, records of production batches, messages on technical changes. Organizes the transfer of information from shift to shift, and also allows you to maintain planning and reporting shop documentation.

5. Data collection and storage (DCA). The function provides informational interaction of various production subsystems for receiving, accumulating and transferring technological and control data circulating in the production environment of the enterprise.

6. Human Resources Management (LM). Generates reports on time and presence at the workplace, provides tracking of compliance with certification. Allows you to take into account and control the main, additional and combined responsibilities of personnel, such as the implementation of preparatory operations, expansion of the work area.

7. Product Quality Management (QM)... Provides measurement data on product quality collected from the production level, allows analysis of correlations and statistical data of causality of controlled events.

8. Manufacturing process management (PM). Monitors the specified production process, and also automatically makes adjustments or proposes an appropriate solution to the operator to correct or improve the quality of current work.

9. Asset Management (Maintenance) (MM)... Support for the process of maintenance, repair of production and technological equipment and tools throughout the entire production process.

10. Product History Tracking (PTG)... Provides information related to products: a report on personnel working with this type of product, product components, materials from a supplier, batch, serial number, current production conditions, individual technological passport of the product.

11. Performance Analysis (PA)... Generates reports on the actual results of production operations, as well as compares with previous and expected results. For example, resource utilization, availability of resources, production cycle time, compliance with plan, standards, and others.

Eleven of the above generic functions that are defined MESA International, make it possible to judge the purpose of class operational control systemsMES. Receiving information directly from production, this kind of system allows you to: control and, if necessary, immediately adjust the production schedule (which is impossible in the ERP system), provide a link between production and business processes, and, finally, collect and transmit data on current production to the ERP system. production indicators in real time.

Production management system classMES is the link between business-oriented ERP systems, supply chain planning systems and real-time activities at the manufacturing level. In its essence and purpose, the production management system is a software layer that allows you to combine various levels of company management into a single information complex. The hierarchy of enterprise management levels and the corresponding automated control systems are shown in Fig. 1.

The undoubted advantage and distinctive feature of this system is the ability to control the production process in real time, to monitor the state of the production process “every minute”. MES allows you to create a flexible information infrastructure that is extremely responsive to any changes in products, production process, workforce composition and the content of working procedures, ensuring efficient management and adaptability of the enterprise's production system. The main functions of the MES-systems listed above are operational scheduling (detailed planning) and dispatching of production processes in the shop. It is these two functions that define the MES-system as an operational system aimed at the formation of equipment operating schedules and operational control of production processes in the shop. The goal of the MES system is not only to fulfill the specified volume with the specified deadlines for certain orders, but to fulfill it as best as possible in terms of the economic performance of the shop. For each workplace, a detailed (indicating the start / end dates of each operation) planned task is formed, corresponding to the optimal production schedule of the work performed. An example of a planned task for a workplace is shown in Figure 2. Figure 2 - An example of a detailed planned task for a workplace Any planned task needs dispatching, therefore, the dispatching function in MES systems has a special place. In MES systems, the DPU function is implemented in the form of a special dispatcher module, with which the dispatcher works. The dispatcher's task is to record all events in the production system: the moments of the actual completion of the processing of batches of parts, equipment failures for various reasons, any advances and delays of certain processes, etc. (Figure 3.4). Figure 3 - Dispatch contour in MES

Further, the MES-system, with a certain time interval, automatically analyzes the information received from the dispatching terminals, and if the actual state of affairs differs significantly from the planned task (the moments of finishing the processing of batches of parts change), the dispatcher is notified by the system about the presence of these discrepancies.

After the dispatcher makes a decision, and this, most often, either a time shift in the work, or a recalculation of the schedule, the adjusted schedule comes into operation again with a mandatory notification to those work centers that were affected by the adjustments.

Figure 4

3. Application of MES production management systems at Russian enterprises

In Russia, production control systems are still a relatively new word in automation. To automate the solution of production scheduling problems at MSTU "Stankin", the software product "Phobos" was developed, which forms the core of the control system for a modern machining workshop, integrating into a single whole automated production preparation, operational scheduling, dispatch control over the state of the processed objects of labor in conditions small-scale and one-off production. MES-system "Phobos" is used in large mechanical engineering, as a rule, in tandem with "heavy" ERP-systems - BAAN or SAP. The system developers are working on the possibility of integration with 1C: Enterprise as well. The industrial operation of the Phobos system has shown that it allows, due to the efficient organization of production, to minimize the norms of material and labor costs, to increase the capital productivity of technological equipment, and to reduce the cost of production.

As Evgeny Frolov, professor of MSTU "STANKIN", developer of the MES-system "Phobos" comments: the load of technological equipment at such plants does not exceed 0.45. (unless, of course, you do not use special production software for drawing up, correcting and supervising production schedules, i.e. MES systems).

Another system - YSB.Enterprise - is intended for small and medium business enterprises that are somewhat "beyond their means" to purchase heavy ERP systems. YSB.Enterprise works on the principle of a two-layer pyramid, where the MES system takes over the functions of the upper control layer.

MES-systems PolyPlan, according to the developer Ravil Zagidullin, associate professor at USATU (Ufa), are most of all designed for automated systems of mechanical processing. Although they can be used for non-automated production. In addition to it, according to his statement, there are no analogues of MES systems specifically for automated production (flexible production, integrated production).

It is necessary to note another advantage of the systems "Phobos" and "Polyplan": the ability to use an integral criterion in the process of optimizing management decisions, which may include several particular criteria, sometimes contradictory. Selection of vector criterion in the PolyPlan system and the system"FOBOS" shown in Fig. 5., 6

Figure 5 -Vector criterion in the MES system PolyPlan

Figure 6 -Criteria for drawing up production schedules in the MES-system "FOBOS"

Using a few particular criteria, a very large number of combinations can be created that can be useful for a wide variety of production situations. For example, in the MES-system "PHOBOS" it is possible to obtain 100 combinations of vector criteria.

In a number of cases, the synthesis of the criterion is carried out in the process of clarifying the production planning task, taking into account the technology of a particular production - mechanical engineering, woodworking (© RFT-Group, www.rft-group.ru, A.R. Zalygin), etc.

The article discusses a huge project in which several companies participated: the creation and implementation of the MES system at the Voronezhsintezkauchuk plant, which produces synthetic rubbers and thermoplastic elastomers (TPE). It is shown how the MES system can improve business processes in an enterprise.

ISUP magazine, Moscow

MES systems

Articles about MES systems appeared in our magazine several years ago, but this topic did not receive much development then. At some point, it even seemed that the MES systems themselves did not take root well in our industry. However, then the time has simply not come for them. Today we will tell you about one implementation, thanks to which it was possible to significantly increase the efficiency of production processes at one of the largest Russian enterprises for the production of synthetic rubber.

Let's start with the main thing: what is MES? This is a kind of intermediate link between production planning systems (ERP) and control systems for the technological process itself (APCS).

The technological process at each enterprise is unique, and nevertheless, there is a similarity: at all factories for a long time the ball has been ruled by the APCS of various types, from PLC to powerful DCS. At the same time, at any enterprise there is a level, the focus of which is the customer - the consumer of the manufactured products. This is where production and logistics are planned, sales are forecast and costs are controlled. Already 15–20 years ago, automated ERP systems were also used to help work at this level ( from English Enterprise Resource Planning - "enterprise resource planning").

Between the levels of the workflow and production planning, a huge number of paper reports have always circulated, which were written by crawlers, operators, engineers, dispatchers and other employees. Paper journals were kept, reports were compiled in Excel tables, regime sheets were printed from the APCS, all these reports were endlessly duplicated and wandered from office to office. A separate complex work that consumes a lot of time was the reduction of material balances. However, gradually, later than at other levels, the automation of "paper" manual labor began to take place here. Applications began to appear, written for the analysis and processing of data related to technological processes. They are collectively called MES.

Today MES ( from English Manufacturing Execution System - "production process control system") are no longer separate applications, but an integrated system that unites production (Fig. 1). With the help of MES, users can receive information about all production operations that are carried out in the enterprise. This happens in a time mode that is as close to real as possible. And this allows us to make production transparent and make management decisions with great speed and mobility.

Figure: 1. MES modules

MES systems are especially in demand at enterprises with multilevel technological processes, which depend on many factors: temperature, pressure, energy consumption, etc.

This is exactly what the Voronezh enterprise of the SIBUR Group Voronezhsintezkauchuk is. Therefore, in 2012, in order to improve the efficiency of production processes at the production site in Voronezh, a large-scale project was launched to implement the MES system.

To imagine the scale of production at the Voronezh plant, let's make a small digression. As you know, oil contains associated gas (APG), which is separated from it during processing. For many years, this gas was simply burned, but APG also has another, much more effective, application: the production of polymers that surround us every day. Everything - from plastic windows to medical instruments, from bottles with mineral water to car parts - is a product of multistage processing of associated petroleum gas.

The key raw material for the production of synthetic rubber is butadiene, which, in turn, is also produced from APG. Butadiene is supplied to the Voronezh site of SIBUR from Tolyatti, as well as from Tobolsk, from the enterprises "Togliattikauchuk" and "Tobolsk-Neftekhim", respectively.

Already in Voronezh, with the help of numerous technological operations, butadiene is subjected to processing, resulting in not only synthetic rubber, but also thermoplastic elastomers (TPE) - materials that combine the advantages of plastic and rubber. The main segment of the first application is the automotive sector, the second - construction.

The MES system implemented at the Voronezh industrial site of SIBUR makes it possible to monitor the entire technological process, from the stage of raw material acceptance to the shipment of finished products to the warehouse.

GE Proficy Software Platform

Building MES required a software platform. The choice fell on a product from General Electric.

GE, a huge corporation that Thomas Edison himself founded 138 years ago, has been known throughout its history as a manufacturer of electrical equipment: compressors, turbines, substations, refrigerators, medical devices and a huge number of other "hardware". However, in recent years, the company has changed its ambitions: now it is the most active in the development of software: the corporation is determined to enter the top-10 of the world's leading developers of software solutions.

One of these solutions is the Proficy software product, which is successfully used to build MES systems around the world.

Considering the specifics of the implementation at Voronezhsintezkauchka, GE had to determine what exactly the customer needed to build a template solution. Using a proprietary methodology, GE has digitized customer requirements and created use cases using Enterprise Architect software. This methodology made it possible to avoid any discrepancies between SIBUR's specialists and software developers. This is how the MES system template was created, in which all the customer's wishes were taken into account.

Enterprise "Voronezhsintezkauchuk"

Let us briefly acquaint the reader with the first enterprise of the group, where the MES-system was to be implemented. Voronezhsintezkauchuk has been producing synthetic rubbers since 1932. Until 1992, ethyl alcohol was used as a raw material for the production of rubber, but later the plant switched to a technology based on the processing of butadiene entering the enterprise. Uninterrupted supplies of raw materials from other enterprises of the SIBUR group allow the Voronezh site to build long-term relationships with customers. The importance of this factor is difficult to overestimate: a large share of enterprises producing synthetic rubbers in the country was closed precisely because of the lack of raw materials.

As mentioned above, the plant produces not only synthetic rubber (used mainly for the manufacture of tires), but also thermoplastic elastomers - TEP, substances that combine the properties of plastic and rubber. Therefore, the customer portfolio of the plant includes both car tire manufacturers (Michelin, Bridgestone, Pirelli, Yokohama, etc.) and companies supplying products for the construction industry.

A separate production facility "TEP-50" produces raw materials for soft roofing, sealants, adhesives. Also, the products of the TEP-50 unit have found wide application in road construction. Polymer-bitumen binders obtained from thermoplastic elastomers can significantly increase the wear resistance of the top layer of the road surface and, in general, extend the service life of the road fund. Note that SIBUR's Voronezh site is the only TEP manufacturer in Russia. More than 80% of thermoplastic elastomers consumed domestically are produced in Voronezh.

"IndaSoft" - system integration

In 2012, the Russian integrator company IndaSoft was invited to implement the MES system at the Voronezh plant. Firstly, because the main direction of its activity is the implementation of MES on a turnkey basis. And secondly, because for this task, IndaSoft specialists have developed software products that meet Russian realities and legislation and are included in the Register of Russian software:
- material balance system (I-DRMS);
- energy accounting system (I-EMS);
- dispatch control system (I-DS / P).

The IndaSoft company has completed over 100 projects at different enterprises, but it was the first time that I had to deal with the specifics of rubber production. The fact is that in this production there is a very complicated accounting: a huge number of components are included in synthetic rubbers, and in addition, 19 energy resources are involved in the production.

Figure: 2. MES integration with SAP

That is why the customer set a task for the integrator: not only to implement the MES system, but also to combine it with the SAP system that automates the work of accountants, financial, personnel and other services. This system was implemented in parallel at the Voronezhsintezkauchuk plant. With the help of the integration of MES and SAP, it was necessary to solve problems related to comparing the plan and the fact of production, transferring technical orders, test results, the problem of residues, coordinating the production of consumption of materials and resources.

For the tasks of integrating MES with other systems implemented in the plant (SAP and LIMS), GE Digital software products were chosen. However, from the very beginning, the MES was integrated with the APCS - a dispatching module was implemented.

Figure: 3. Mnemonic diagram in the control room, reflecting the technological processes taking place at the enterprise

Already in 2014, the dispatcher of the enterprise saw the entire production on the monitor (Fig. 3): which lines are functioning and which are standing, how efficiently the work is going. Previously, the dispatcher found out this information by phone: operators and other employees serving the automated process control system called him and reported what was happening. Thus, the dispatcher's information depended on the employees, all of it had to be recorded in paper logs, and decision-making took a lot of time. Now information is received in a mode that is as close to real time as possible, directly from the sensors of the automated process control system. And the calls now go in the opposite mode: the dispatcher calls the operator and indicates that his line is not working effectively enough or some kind of malfunction is observed. Decisions are made very quickly. In addition, the need to fill out paper journals has completely disappeared, which frees you from unnecessary labor and eliminates human error, because all information about the technological process goes to MES automatically.

Here it should be indicated separately that the connection between the APCS and the MES system is one-way. The MES-system receives information about the progress of technological processes from different process control systems of the plant, but no information and no control signals can go back through the network to the process control system. Feedback is carried out only through people: for example, on the same phone. This is important primarily for security reasons.

Figure: 4. In the control room of the TEP-50 installation: on the wall - video information from the shop; on the operator's monitor - a mnemonic diagram of the workflow

However, the “hottest time” in the work on the implementation of MES came in the second half of 2014. By the summer, all the necessary applications were written, all the necessary equipment was prepared. Six months remained until the new year. During these six months, it was necessary to implement the system, because from January 1, a new financial year begins and MES was supposed to come into operation in parallel with SAP. This record-breaking implementation was completed on time.

How it works

The project for the implementation of MES at the Voronezh site of SIBUR is truly unique, since it was here that for the first time in Russia it was possible to integrate two systems - MES and SAP. Thanks to the integration, it became possible to reduce the material balance of the plant as quickly as possible. The data on the balance of finished goods in the warehouse is updated in MES and transmitted to SAP on a daily basis.

Let us explain with an illustrative example: as soon as a part of a batch of rubber comes to a storekeeper, he records this event in a computer. The information is immediately entered into the system and sent to SAP, where it is also seen.

Also, this batch is sent to the laboratory for quality control. Synthetic rubbers can have a wide variety of compositions. Different customers need different rubber. The quality of the batch is recorded by the employees in the laboratory system LIMS, from there this information goes to the MES, which sorts the finished products for a specific customer. There are a lot of sortings every month, so it is clear that automation has made the workflow much easier, faster and more streamlined. In addition, it is now possible to promptly ship products to the client without storing them in the warehouse.

On the basis of all the data obtained, the material balance is brought down once a day, as well as the economic balance is brought up - an exceptional situation for our industry, where balancing takes place once a month and requires very large labor costs. Today, balancing balances at Voronezhsintezkauchuk has become a very convenient function that the company needs.

The same balancing occurs for each energy resource.

And all this data (we emphasize - reliable data!) In real time can be seen by all employees of the enterprise at different levels: engineers, dispatchers, heads of departments, general director, etc.

Let's note the key business results of MES implementation and SAP / MES integration:
- receiving in SAP (via MES) primary data from metering devices with audited change;
- a transparent algorithm for the formation of aggregated and agreed indicators of the plant's performance based on measured data
- access to the primary measurements of the APCS at all levels of production management, quality control of the APCS data;
- a single reliable set of data for the formation of operational reporting, all services of the enterprise receive data from a single source;
- a single source of quality data, automatic data transfer to MES and SAP ERP for certification;
- operational control of parameters of safe and effective maintenance of technological modes from any place.

It was about a month ago. Vasily came to our office. He is a top manager of a company that manufactures equipment for theater stages. From the doorway, he said that he needed an MES system or an APS system and that he had not yet fully decided which of them. "Why MES-system?" I asked.

For several months I have been studying the issue related to solving our production problems. I met with representatives of several companies producing MES and APS systems. They said that their systems solve our problems. Moreover, I was told that only such systems are capable of solving our problems. Do you also have an MES system?

No, we have an ERP system. It doesn't matter, forget about these abbreviations. Let's just talk about your problems.

- Do you think your system is able to solve them?

Vasily, the problems are solved by the company's management. And the software only helps to do this. But software by itself does not solve problems. I think that some of your problems can be solved without software, and some can be solved by our software. What do you think are your problems?

It's simple: we never do anything on time. This is our main sore. And a bunch of others. For example, very often when assembling a unit, it suddenly turns out that there are simply no necessary components for it. And heaps of other components.

And this problem can be solved using the MES system?

I was shown a presentation. I really liked it. The fact is that in the MES system, you can plan everything in advance, and if you do everything as planned, then everything will be fine. There are graphs, everything is very clear.

The key phrase is "do as planned," I don't think you can do it. What do you think 50 years ago there were MES systems?

Of course not.

Does this mean that before absolutely all companies never did anything on time? Both Ford and Toyota and thousands of other manufacturers, some of which have been in operation for more than one century. According to the people who presented the MES system to you, there is no other way to solve this problem.

I don’t know, I didn’t think about it.

By the way, did you ask them how this system will be integrated into all other business processes of the company? Well, there, I don't know, purchasing, sales, warehouse, finance, etc.

Hmm, yes, interesting. We have not discussed this issue, I don’t know ... I’ll ask.

What are you producing?

Winches. Big winches, not for cars, but more serious.

Good. If all the components are in stock, how long does it take to produce one winch?

Uh, I think about five hours.

And if I order a winch from you right now, when will I receive it?

Mmm, I think that in ten days for sure.

It's strange. You have a pretty good ratio of net labor intensity to total lead time. Something around 15. This is an excellent ratio for our country. In the west, and especially in Japan, it is certainly much less, but in Russia it can be hundreds. And you have fifteen. Very strange ... Well, okay, let's figure it out further. What component do you need to buy the longest?

Engine.

How long does it take to purchase it?

Maybe forty days.

Do you keep them in stock?

Wait a second. Where then ten days from?

Vasily is confused.

I don't know, I always thought that ten days is definitely enough for us.
Then it becomes clear to me that their control ratio is actually "traditional", something about a hundred.

How quickly can you buy the rest of the components?

Quickly. A day or two.

Well, here's your first problem. It's called the "engine". Why don't you keep a small buffer of engines in stock?

We thought about it. But it doesn't work. The fact is that they come to us with couplings. The couplings are very different. There are about a dozen different engines, and there are much more couplings. Therefore, there are a lot of combinations. We'll have to keep a huge number of these engines in stock.

Can you install the couplings yourself?

Yes, it's not difficult. We have production.

Why don't you do this?

Uh, I don't know. It has always been that way.

I think the solution to the forty days problem lies somewhere around this point. Consider installing the couplings yourself and keep a small motor buffer in stock. Manage your buffer on an order-what-you've-spent basis. I took the engine - order it from the supplier. This is the first thing. Second. Never start a production job without completing a previous job. Then you will get rid of the problem called "when we do something, we find out the missing parts." Correctly line up tasks, always do the most burning ones.

I do not know. I'll talk to the boss, but he caught fire with the MES system. Everything is planned very well there. The boss wants to approve the plan and not think after that about disrupting the deadlines.

This, of course, is his right. What if something goes wrong?

Not understood. What do you mean wrong?

Well, look. You have people of different qualifications, you have different machines. It would seem that everything is complicated. MES (and even more so APS) system takes all this into account when planning. So?

Yes, I saw it myself at the presentation.

Now for a simple situation. God forbid, of course, but let's imagine tomorrow, 08-00. One of the key engineers (locksmiths) falls on the way to work and breaks his leg. Without it, one of the products, which, as luck would have it, is in the plan for today, cannot be made. What to do?

Well, I don't know. MES systems can quickly reschedule everything.

No doubt. But it is not MES systems that are planning, but management. You said yourself that the plan is approved by the boss. But unfortunately he is on vacation now ... What will you do?

Well, I don't know exactly, I didn't think about it. I think the production manager will decide what needs to be produced right now.

Vasily, I have given you one of the simplest cases of external influence on your production plan. In fact, there are many more such impacts and they can be much more complex. And they will happen every day, unfortunately. As a result, your production manager will make "strong-willed decisions" every day. And after a while you will make plans only because “you have made a lot of money and don’t throw it away”.

So what do you suggest?

Have you read Goldratt's Target 1?

No, who is it?

Goldratt is an amazing guy who came up with an ingenious (like anything simple) management system. Let's do it this way. You will read it, and then we will meet again and just talk. I highly recommend it. In my company, all processes are based on this theory. Over the past two years, the company has grown three times.

And here's another question. Is your system able to detect the position of the vehicle?

Lord, why do you need this?

You see, our chef very often interferes in the process and calls the drivers when they have already loaded and left, finds the nearest one, returns him back, he is unloaded and loaded with an urgent order, because someone there called the chef. Yes, and in production it often happens that the chef intervenes and demands to produce something else ...

Well, here's another problem for you. She is called "chef". You told me about some of your problems and instead of trying to solve them, you want to close them up with plasticine.
Then I drew very simple production diagrams for him on the board, but this is a topic for a separate post.
And he left in thought.

Literally a few days after this meeting, I flew to Novosibirsk. More precisely in Akademgorodok, or rather in the Technopark of Akademgorodok. All production processes in which are built on the basis of Goldrat's theory of constraints. This is an amazing sight.

I have details of that trip in

History of planning systems

Ancient history

The idea of \u200b\u200bscheduling work in an enterprise, be it a factory, a factory, or the process of building a pyramid, is as old as the world. As soon as people learned to handle numbers more or less tolerably, a desire immediately arose to subjugate production processes with the help of these numbers. Also, people have long understood that extreme value is not always the best, since in our world all kinds of restrictions always oppose it. Combinatorics in the nature of things and events have always existed. And there was always a desire to remove chaos, to organize work in time and to fix this order, even if it was found empirically. At the beginning of the 20th century, the well-known specialist in the organization of production G. Gantt (1861-1924) first formulated, in relation to the Bancroft company, which produces cotton fabrics, the following three simple rules for organizing work:

• The order in which work is to be done is now determined in the office by the white collar rather than the dyer.
• An accurate record of the best dyeing method in any shade is kept in the office, respected by the master and no longer depends on the dyer's notebook or memory.
• All dyers and machinists are financially rewarded when they follow instructions or, conversely, are punished when they do not.

And G. Gantt fixed this order of work graphically in the well-known diagram, which we now call by his name. A start was made. It remains only to find a way to calculate the optimal sequence of work that cannot be violated. After the introduction of these principles of organizing production at a textile factory, with a significant reduction in the working day by 25-30%, the output of products increased, and wages increased by 20-60%. ...

New story

It is customary to calculate the "new" history of solving problems of optimal planning in production from 1939. It was then that the publishing house of the Leningrad University published a small book by the young professor L.V. Kantorovich "Mathematical methods of organization and planning of production". This monograph laid the foundation for scientific methods in the planning and organization of production on the basis of the then emerging direction of economic mathematics, which subsequently took shape in mathematical programming.

The reason for the "lack of demand" was the lack of the possibility of implementing the proposed models and algorithms, since There was no computer yet and before the appearance of the first prototype of the programming language there were still ten long years.

The appearance of the first computers significantly stimulated the development of work in the field of mathematical economics, organization and production planning. An effective method for solving integer problems (R. Gomori), the branch-and-bound method (A. Land, V. Doig, and J. Little), the method of dynamic programming (R. Bellman), etc. have been developed. All these methods of finding the optimum in the environment combinatorial world found application in various areas of economics and production. One of these applied areas of mathematics called Scheduling theory just "took up" the solution of a large class of tasks of planning work in production.

The task of planning technological operations on machine tools, published by S.M. Johnson in 1954, which showed that scheduling already for three machines belongs to the class of problems that are difficult to solve in an acceptable time (the so-called class NP-complex tasks) did not discourage the factory specialists of the first departments of the automated control system. If the first benefits of computerization could only be used by government agencies, grinding Leontiev's multidimensional balance models or drawing up five-year plans, then with the cheapening of computer technology and the appearance of the first serial computers, it became possible to solve planning problems at the enterprise level and even for workshops and individual sections. An enterprise was considered advanced if it developed its own automated control system, if it tried to build work schedules for its machine park using its own production scheduling systems.

The development of new applied branches of mathematics and affordable computing technology of the class IBM 360/370, ES computers 1020 - 1060 did their job in the 70-80s - they were a catalyst for the emergence of the first automated control systems and allowed at least in some approximation to solve the problems of getting rid of the chaos of combinatorics "in the world of machine tools and parts."

Recent history

Whatever new plots for the treatment of time science fiction writers come up with, this time runs almost exponentially. For some twenty years, mankind "overtook" Moore's law and instead of mainframes and home-grown automated control systems, new "animals" of the zoo are now roaming the IT market, which is also called enterprise and process management systems... The main varieties of these systems that are currently responsible for drawing up work plans in production are systems of the ERP, MRPII, APS and MES classes. If their ancestors, the automated control systems, were content with the possibility of drawing up volumetric calendar plans (less often, equipment operation schedules), calculating financial prospects for the next five years with stable demand and payroll accounting, then the new systems include more and more new functions for automating activities enterprises in the dynamically developing market of goods of the latest consumer society. But the main function, as before, is the ability to draw up a work plan. It is this function that ultimately makes it possible to understand who, when and what should do. How is planning in these systems and which one is intended for which cases?

Planning inERP

We will not dwell on the description of the functionality ERP-systems not only due to the fact that a lot has been written about it, but also due to the fact that ERP systems, in fact, are not a direct tool for planning work in an enterprise. After ten years, consultants and users have finally come to believe that ERP is, first of all, a corporate information system, an enterprise management system, a kind of circulatory and nervous system of an industrial organism, connecting islands of logistics of numerous organs performing certain functions (workflow , management of purchases, supplies, warehouse stocks, etc.). The nature of work planning, technological operations on machine tools and other units of technological equipment in ERP systems can be said in one phrase - planning in most systems is based on the old MRPII standard without taking into account the current load of this equipment and the state of processing of products. Those. in fact, any detailed ERP plan would be nearly impossible to implement. Any planning at the ERP level is limited only to the formation of a volumetric monthly (ten-day) plan. It is not possible to promptly correct such plans, which is why their implementation presupposes strict executive discipline in all divisions of the enterprise involved in the production chain. Those. we can talk about the organization of production controlled by ERP, as production with a certain margin of "stability" in relation to the emerging deviations from the compiled volumetric plan. In this case, the whole burden falls on the performers: "as you wish, but fulfill the planned task by the calculated date!" And, what is especially important, ERP, having issued a task to all departments, when there is a need to adjust plans, is not able to cope with this, because any recalculation will give the same picture of the overall task - tasks in volumes, but not in detailed terms for products and operations, which is required for control at the workshop level.

Planning inAPS

From the point of view of accurate planning of work in enterprises, systems of the APS (Advanced Planning & Scheduling Systems) and MES (Manufacturing Execution Systems) classes are of interest.

APS-systems, which appeared on the market in the mid-90s, are already a direct tool for planning work at the enterprise. Despite the unambiguous designation, many authors and even developers interpret this name in different ways: "optimized production planning", "improved planning", "improved planning", "advanced planning", "optimized and synchronous planning", "precise planning", "Operational planning" and even "careful planning"!

Agree, there are so many interpretations that the question arises - what, in fact, is the matter? Compared to what is advanced, improved, how accurate, what is synchronous, what is optimized and how fast?

Expanded and refined.

In the early 90s, after the first experiences of ERP implementation, understanding the advantages and disadvantages of planning according to the MRPII standard, enterprises faced the main problem - planning reliability. Reliability and accuracy in time. The dynamics of the market, the trends of the JIT concept demanded from enterprises more precise delivery times, full participation in supply chain management. The imperfection of planning methods with MRPII required a revision of "values" - what is important in planning? Speed, contradicting accuracy, and what are these indicators for? It turned out that without solving the problem of supply management, without the ability to predict the exact dates of production, an enterprise is a thing in itself. Therefore, the main goal for the new generation planning systems - APS - was to solve the problems of automation of supply chain management (SCM - Supply Chain Management), and this APS functionality, implemented by the ability to plan all work in time, taking into account capacity utilization, has a dual purpose - it is implemented both for the enterprise, which is the object of the entire chain in the dynamic market of goods, and for the objects of the enterprise itself - workshops, sections and divisions. Thus, the scheduling capabilities in APS are expanded and improved relative to the MRPII standard.

Synchronicity.

The concept of synchronicity should be understood in APS, on the one hand, as the ability to plan materials, resources and at the same time to build a schedule taking into account the real load of equipment in time. On the other hand, synchronicity is also expressed in the fact that the schedules are built for all departments of the enterprise, taking into account the delivery times of partners and the schedules for all these production structures are always interconnected in time, since they are obtained from the general schedule of the entire enterprise.

Efficiency.

Efficiency for APS is the ability to determine the production time for a particular order in the shortest possible time. Efficiency in terms of dispatch control and prompt recalculation of schedules, as a rule, has nothing to do with APS, because if external restrictions do not change (violation of delivery times by partners, other unforeseen delays) and a new product is not added to the order book every five minutes , then recalculating the schedules will give nothing. Taking into account internal disturbances from numerous subdivisions (equipment breakdowns, rejects in operations, etc.) can lead to a significant increase in the dispatching contour with the existing dimension of the problem.

Accuracy and Optimization.

The accuracy and optimality of the generated schedules is the prerogative of the algorithms of any planning system.

Compared to MRPII algorithms, APS scheduling algorithms simultaneously take into account both material needs and plant capacity, taking into account their current and planned load. The APS algorithms take into account changeovers and some other parameters of the technological environment, which for some reason pessimists call “constraints”.

There are many well-deserved epithets to APS algorithms, but in some cases, in a fit of enthusiasm, these systems are attributed to features that baffle even specialists. In particular, it is said that the algorithms of APS-systems are based on simulation models, neural network models, planning based on a knowledge base, now fashionable heuristic methods such as genetic algorithms, simulating annealing and even linear programming (!).

In fact, the scheduling algorithm in APS is quite simple. There are many operations for the whole variety of manufactured products, many machines and for each product there are restrictions - on the timing of production, on the availability of material, etc. Restrictions are divided into important and not so. First, on the first pass of the algorithm, a schedule is drawn up taking into account the feasibility of important constraints, for example, the absence of violation of delivery times. If the schedule is received, then it is considered valid and is taken as a base for further "optimization" - on subsequent passes of the algorithm, an attempt is made to take into account the remaining less important constraints. This is not really an optimization. This is nothing more than an iterative process of getting permissible schedule taking into account the new constraints introduced at the new iteration, i.e. a very simple heuristic. In some cases, the planning process is simplified even more - first one plan one detail, then another, until all the many details have been planned. In this case, the estimate of the obtained schedules relative to the actual optimum can be quite low, but it should be noted that if we draw up a schedule for several thousand pieces of equipment from hundreds of thousands of operations for a month or six months, then we can accept this fact. Especially considering that at the next stage, MES systems will be responsible for the actual implementation of the production schedule. Thus, by simplifying the scheduling algorithm, the APS developers made it possible, within the existing computing power, to obtain acceptable schedules and more or less accurately predict delivery times. At the same time, APS systems do not set themselves more complex tasks such as minimizing changeover times, transport operations, reducing the amount of equipment involved, etc. in the constructed schedules, since taking into account these requirements will inevitably lead to a heavier algorithms and the inability to obtain schedules for large dimensions. In this regard, APS systems are armed with an extremely limited set of planning criteria. It should be noted that this existing possibility of obtaining at least admissible schedules (within half an hour) did not appear in vain in the mid-90s. The increase in the performance of computers with a simultaneous decrease in their cost, once again, was a catalyst for progress in the field of production management.

Other features.

Although it is said that APS can reschedule, firstly, not all APS systems have a dispatching loop, and secondly, the rescheduling frequency in APS is due to the frequency of new orders (real-time feedback for APS is considered excessive), differences from MES, which do this operation much more often (for a task of much smaller dimension, adjusting the plans of only individual shops), since they react to any change in the course of the technological process. Constant correction of production plans is a typical phenomenon for small-scale and single-type production facilities; they are often referred to in the literature as "custom-made". Note that APS vendors in some cases use MES integration to create a more accurate feedback loop for custom manufacturing.

The planning horizon in APS is rarely indicated unambiguously - shift, week, month, up to six months. But no matter how one guesses about the “average size” of the planning horizon, for APS systems it is determined very simply, based on the main task, the system's functionality, which is supply chain management. The duration of the planning horizon in APS systems is always the difference in time between the moments of issuing the most distant orders from the entire portfolio of orders of the enterprise and the current date, since when a new order appears and the entire schedule is recalculated, it is necessary to determine not only the timing of its production, but also the possibility non-violation of the terms of execution of already launched orders.

So, it is these new opportunities, driven by the need for supply chain management, that are the reason that the growth rate of APS systems has become significantly ahead of the growth rate of solutions in the ERP segment. Along with foreign systems (Berclain, Chesapeake Decision Sciences, CSC, Fygir, i2 Technologies, Manugistics, Numetrix, Optimax, Ortems, Preactor, Pritsker, Paragon Management Systems, ProMIRA, Red Pepper Software, Thru-Put Technologies, etc.) in recent Over the years, domestic products began to appear (infor: APS, Adexa eGPS, etc.). Fears that APS would grow to new ERPs were, perhaps, only among journalists, since it was initially clear that APS systems were not responsible for finance, procurement, document management and other ERP transactional functions, but the leading manufacturers of ERP systems (People Soft , SAP, Oracle, SSA Global, JD Edwards, Marcam, etc.) reacted quickly enough and expressed a desire to share their solutions with APS products. Gradually, this collaboration developed into a natural need for integration at the level of the ERP planning core, which can be replaced by an APS system. At the same time, APS can be supplied as a separate product.

Planning inMES

MES systems are said to have been around for over 30 years. Unfortunately, the authors of the article, whose total work experience in the field of production planning and automation is 45 years, did not come across this abbreviation in the literature twenty years ago. Be that as it may, with MES-systems everything is more or less extremely clear, except for one thing - they are constantly confused with APS-systems. To understand what MES systems really are, let's take another look at the regulated composition of MES functions, the number of which is exactly eleven (www.mesa.org, www.mesa.ru, www.mesforum.ru):

1. Condition monitoring and resource allocation (RAS).

2. Operational / Detailed Planning (ODS).

3. Dispatching production (DPU).

4. Document Management (DOC).

5. Data collection and storage (DCA).

6. Personnel Management (LM).

7. Product quality management (QM).

8. Manufacturing process management (PM).

9. Management of maintenance and repair (MM).

10. Tracking Product History (PTG).

11. Performance Analysis (PA).

As we can see, in this list there is no SCM function, which is the main one in APS systems. Despite the seeming, at first glance, variety of MES functions, it must be understood that all these functions are operational in nature and regulate the corresponding requirements not for the enterprise as a whole, but for that unit (workshop, site, department) for which work is being planned. ... It should also be understood that functions such as document management, personnel management are the management of shop documents (work order, reporting sheets, etc.) and shop personnel. The main functions of the MES systems listed above are operational scheduling (detailed planning) and dispatching of production processes in the shop. It is these two functions that define the MES-system as an operational system aimed at the formation of equipment operation schedules and operational control of production processes in the shop.

The MES-system receives the scope of work, which is either presented by the ERP at the stage of volumetric scheduling, or is issued by the APS-system in the form of a work schedule acceptable for the enterprise, and in the future it not only builds more accurate schedules for equipment, but also in online monitors their implementation. In this sense, the goal of the MES-system is not only to fulfill the specified volume with the specified deadlines for certain orders, but to fulfill it as best as possible in terms of the economic performance of the shop. We have already said that APS systems form some initial work schedules of the first degree of approximation even before the implementation of production plans begins. At the same time, due to the large dimension of the problem, many technological and organizational factors are not taken into account. The MES-system already at the stage of execution, receiving such a preliminary plan, optimizes it according to a number of criteria. At the same time, after optimizing and building a new schedule for the shop's work, very often, due to the compaction of the equipment, additional reserves are found, and it becomes possible to fulfill additional orders within the planned period. This achieves the effect of increasing the throughput of production structures.

Unlike APS-systems, MES-systems operate with smaller assignment dimensions - up to 200 machines and 10,000 operations on the planning horizon, which is usually no more than three to ten shifts. The reduction in dimensionality is due to the fact that MES takes into account a much larger number of technological constraints. Another difference is that MES systems usually operate not with one or two scheduling criteria, but often with several tens, which allows the shop manager to build a schedule taking into account various production situations. And only MES-systems operate with the so-called vector, integral scheduling criteria, when several particular criteria are collected in one criterion. In this case, the dispatcher, making up a schedule, can indicate what he wants to see in a specific schedule - a decrease in the calendar duration of the entire task, a decrease in the duration of changeover operations, the release of machines with a small load, etc. Efficiency of scheduling and recalculation is also the prerogative of MES, since recalculation can be carried out with a discrete of one minute. This does not mean, of course, that every minute the worker will be given new tasks, but it means that all processes in the workshop are controlled in the mode real time and this allows you to anticipate all possible schedule violations in advance and take appropriate measures in time.

Algorithms of MES-systems, although they are based, in most cases, on heuristics, but, as a rule, are much more complicated and "smarter" than APS algorithms. First, the MES algorithm finds a feasible solution taking into account all the constraints and the selected criterion (particular or integral). Later, at the optimization stage, the search for the best schedule is carried out. Of course, the resulting schedule is also not optimal in the full sense of the word, since the search for the optimum in such problems is always accompanied with significant time costs (MES systems construct schedules in 0.1 - 5 minutes using modern technology), but the resulting schedules, as a rule, are is already much closer to the optimum than the schedules built by APS systems.

In some cases, MES systems can create schedules not only for machines, but also for vehicles, service teams and other maintenance devices. Not for any other systems such planning features as the formation of technological fees, planning the release of products with parallel planning of the manufacture of the required set of equipment (devices, unique tools).

An important property of MES systems is schedule feasibility. Built into the ERP planning loop, APS systems draw up production schedules only if new products or works are added to the order book, it is extremely difficult to adjust them in real time, which leads to serious problems in using APS systems in small-scale production. In such cases, MES systems work more flexibly and efficiently, recalculating and adjusting schedules for any deviations in production processes, which increases the flexibility and dynamism of production. While APS schedules are more suitable for large-scale production, where there are usually no abrupt deviations from the production program (stable production), then MES-systems are indispensable in small-scale and custom-made production. At the same time, if for APS systems a workshop with a large volume of technological and operational information is to some extent a "black box", then MES systems, when performing tasks, rely on the principle of calculating and correcting production schedules based on the actual state of production. These systems are quite sensitive to deviations in the time of technological operations, to unforeseen equipment failure, to the appearance of defects in the process of processing products and other disturbances of an internal nature.

Unlike systems of ERP and APS classes, MES systems are subject-oriented - for mechanical engineering, woodworking, printing, etc. Therefore, they fully reflect the features of the technology of specific production processes and often include developed means of supporting the technological preparation of a particular type of production ... Very often MES-systems have means of integration with CAD / CAM systems. It is characteristic that, according to Western data, the introduction of MES at an enterprise not only ensures the preparation of detailed production schedules, but also has a positive effect on quality management and the level of service of technological equipment.

Reinoud Visser & Jan Snoeij, MES Product Survey 2003

There are solutions on the market both for systems with a discrete nature of production, and for production with a continuous nature. The most difficult from the point of view of planning accuracy and feasibility of plans are systems of the first type, especially with a "custom-made" type of production.

The market for MES systems is developing very dynamically (on the resource of the MES association - www.mesa.org, the reader can find references to more than fifty MES systems). As with APS systems, leading ERP vendors are interested in integrating their products.

Strict functionality of systems, "stability" of the implemented production plans and schedules

Can MES completely replace APS?

To give a reasoned answer to this question, we note that the implementation of synchronized detailed schedules drawn up at the APS level is no longer just a matter of correcting volumetric ERP plans, but of maintaining their stable "sustainable" execution: the entire production system must have a margin of stability in relation to to small deviations arising in individual shops. Synchronized APS schedules should not be adjusted frequently, especially if this is not due to external factors (delayed delivery of raw materials, new urgent orders, etc.). And in order for each production division of the enterprise to be able to independently "extinguish" the deviations that arise in it, the use of MES is already required.

In MES, on the contrary, no a priori "stability" of the compiled production schedules is assumed, moreover, their implementation is obviously "unstable" (mathematicians would say here that such a schedule is a so-called structurally unstable object), because it assumes the possibility of operational correction in any time at the request of the dispatcher. Bringing some analogy with the means of transporting bulk goods, ERP + APS could be compared with a good stable truck, and MES with a team of cyclists, to whose trunk they attached a bag with the transported cargo.

We can now rephrase the original question about the interchangeability of MES and APS in another way: how, after all, is it better to transport cargo

On 100 bicycles (here you have to pedal - after all, a bicycle unstable)

On one sustainable truck?

Take your time, dear reader, with a seemingly obvious answer ... remember that resilient systems are generally poorly managed. One should always ask oneself the question: “What road are we driving? And what will happen when the highway suddenly ends and, for example, a forest is on the way of traffic? " It is not difficult to predict that in this case cyclists have a good chance to carry at least part of the load to the destination ... but with a stable truck, alas.

Of course, in reality, not everything is so tragic. If planning is carried out for small enterprises with no more than 200 machines, then, in principle, MES and APS could be considered conditionally interchangeable. Especially when it comes to "custom-made" production. At the same time, delivery schedules and times will be much more accurate, but MES lacks some APS functions, for example, planning material requirements, since MES are executing systems and their task is differently - to execute the work plan as best as possible. APS is the level of detailed planning for the entire enterprise, and MES is the level of a shop, site, department.

Can we say that MES = APS or that one system is simply part of another (such opinions, alas, are often expressed in periodicals)? The answer is unequivocally negative: of course, NO; - despite the external similarity in their functional capabilities, these systems do not coincide in the nature of the implementation of the production schedules they create, just as stable and unstable systems do not coincide in their dynamics. Those planners that form strict directive plans (ERP + APS) are usually called Push Planning Systems - systems "push plan", and those that promptly adjust plans in the course of their execution are called Pull Planning Systems - systems "pull the plan". Think for a moment, can one person move a load while pushing and pulling it? Of course not! Now it becomes clear why the statement is true: MES<> APS... These systems do not conceptually coincide and are not part of each other, and this difference must be recognized quite clearly.

Recently, in pursuit of marketing bonuses, many developers began to position their products as APS or MES solutions. In some cases, these are systems for technological preparation of production, warehouse logistics systems, and even ordinary databases. We think that the reader, having familiarized himself with the distinctive features of APS and MES in this article, can easily figure out what kind of product he is offered, despite the marketing tricks.

So, we see that for an enterprise, from the point of view of predictability and transparency of the planned timing of production, optimal production, the following planning mechanisms are needed:

Planning of materials and resources according to BOM (Bill of Material) throughout the planned range of the enterprise;

Supply chain management;

Detailed planning and operational dispatch control of equipment operation schedules;

This is only possible if we use all three systems - ERP, APS and MES together.

ERP, APS, MES - although they are completely different systems with different functionalities, designed for different purposes, but at the same time they can not only perfectly coexist, but also complement each other in terms of creating a powerful planning system at the enterprise that covers all existing tasks ... In some cases, we hear from maximalists calls to increase the functionality of APS or MES to the level of ERP. Can this be done? In principle, you can. Gather a development team and tell them: “There is MES (or APS) in stock. We need to make ERP out of it! " All this can be done. How can you feed a cat to the size of a Caucasian watchdog. But then who will catch the mice and guard the house? ...

"Stay with us!"

In the next part, the authors will tell the reader about the features of scheduling in MES systems, about the types of scheduling criteria and how to choose them, about how an optimal solution is sought in a multi-criteria environment, about what task priorities are and how to assign them and about how MES systems are created.

Literature

1. Production management. Ed. S. D. Ilyenkova.-M .: UNITI-DANA, 2000. - 583p.

2. Timkovsky V.G. Discrete mathematics in the world of machine tools and parts. - Science, M .: 1002 .-- 144p.

3. Gavrilov D.A. Manufacturing management based on MRP II standard. - SPb .: Peter, - 2003 .-- 352s.

4. Bermudez J. Systems of optimized production planning: a new fad or a breakthrough in the field of production and supply chain management? Manufacturing overview. AMR Research.

© 2007
Doctor of Technical Sciences, Professor, Moscow State Technological University "STANKIN", Department of Information Technologies and Computing Systems.

Zagidullin Ravil Rustem-bekovich © 2007
Doctor of Technical Sciences, Professor, Ufa State Aviation Technical University (USATU), Department of Automated Technological Systems.

Source of information: Machine park magazine, No. 10, 2008.

MES systems are computerized systems used in manufacturing to track and document the conversion of raw materials into finished products. They provide information to help decision makers understand how current plant conditions can be optimized to improve product output. MESs operate in real time to provide control over multiple elements of the manufacturing process (e.g. entrances, personnel, machines, and support services).

How it works?

MES unified management systems can operate in several functional areas: managing product definitions during their life cycle, resource planning, order fulfillment and scheduling, production analysis and downtime management for overall equipment effectiveness (OEE), product quality or material tracking, etc. etc.

Such a system creates a “built-in” record, capturing data, events and results of the production process. This can be especially important in regulated industries such as food and beverage or pharmaceuticals, where processes, events and actions may need to be documented and confirmed.

The idea of \u200b\u200bMES can be seen as an intermediate step between an enterprise resource planning (ERP) system and control and assembly management (SCADA) or a process control system.

In the early 1990s, industry groups such as the International-Manufacturing Enterprise Solutions Association (MESA) were formed to regulate the complexity and provide guidance on the implementation of MES Systems.

Benefits

These systems help create flawless manufacturing processes and provide real-time feedback on requirements. Plus, they provide all the essential information in one place. Other benefits of a successful MES implementation can include:

1. Reduction of the amount of waste, their processing and disposal, including in a shorter time.
2. More accurate collection of cost information (e.g. work, downtime, and tools).
3. Increased uptime.
4. Introduction of paperless work.
5. Reduce surplus by eliminating inventory on a case-by-case basis.

MES varieties

A wide variety of MES systems have emerged from the extensive use of collected data for a specific purpose. Their further development during the 1990s led to an increase in their functionality. Then the Manufacturing Industries Association (MESA) implemented a structure, defining 11 functions that limited the scope of the MES. In 2000, the ANSI / ISA-95 standard combined this model with the Purdue Reference Model (PRM).

A functional hierarchy was defined in which the executive MES were at level 3 between ERP at level 4 and process control at levels 0, 1, 2.Since the publication of the third part of the standard in 2005, the activity at level 3 has been divided into four main operations: manufacturing , quality, logistics and maintenance.

Between 2005 and 2013, additional or revised portions of the ANSI / ISA-95 standard further defined the hardware composition of MES systems, covering ways of internally distributing functions and exchanging information both internally and externally.

Functional areas

Over the years, international standards and models have expanded the scope of these tools in terms of their performance. Typically, the purpose and function of MES systems include the following:

1. Product definition management. This can include storing, versioning, and exchanging data with other systems such as product manufacturing rules, BOM, resource counting, process checkpoints, and quality data, all of which focus on defining how a product is created.
2. Resource management. This may include registering, exchanging and analyzing information about resources for the preparation and fulfillment of production orders that are possible and available.
3. Planning (production processes). These actions define the production schedule as a set of fulfillment orders to meet production requirements, usually derived from enterprise resource planning or specialized advanced planning systems, to ensure optimal use of local resources.
4. Sending production orders. Depending on the type of production process, this may include the further distribution of lots, runs and work orders, their distribution to work centers and adaptation to unforeseen conditions.
5. Execution of production orders. While the actual execution is done by process control systems, MES can conduct resource checks and inform other systems about the progress of manufacturing processes.
6. Collection of production data. This MES function includes the collection, storage and exchange of process data, equipment status, material information and production logs, either in a filing cabinet or in a relational database.
7. Analysis of production performance. It is getting useful information from raw collected data about the current state of production. These include performance reviews (WIPs) and historical performance (such as overall equipment efficiency or any other similar metric).
8. Production track and tracing. It is registering and retrieving related information in order to present a complete history of sales, orders or equipment. This area is especially important for industries related to the health sector. This is, for example, the production of pharmaceuticals.
9. Digitization of complete data from logs to the interface of digital devices using the edit lock function, as well as output of data from SCADA to a common database.

Communication with other systems

The MES Manufacturing Execution System integrates with ISA-95 (the previous Purdue model, "95") with multiple relationships and links. The collection of systems operating at ISA-95 Level 3 can be called Manufacturing Operations Management (MOMS). Besides MES, there is usually a laboratory information management system (LIMS), warehouse management system (WMS), and a computerized service management system (CMMS).

From the MES point of view, the possible information flows are:

• in LIMS: requests for quality testing, sample samples, statistical process data;
• from LIMS: quality test results, product certificates, test results;
• in WMS: requests for material resources, definition of materials, delivery of products;
• from WMS: material availability, material phased batches, product shipment;
• in CMMS: data-handling equipment, its purpose, service requests;
• from CMMS: maintenance progress, equipment capabilities, maintenance schedule.

Communication with level 4 systems

Examples of systems operating at ISA-95 Level 4 are Product Lifecycle Management (PLM), Enterprise Resource Planning (ERP), Customer Relationship Management (CRM), Human Resource Management (HRM), Process Execution System (PDES).

In terms of MES systems, examples of possible information flows are:

• to PLM: production test results;
• from PLM: product definition, transaction accounts (routes), electronic work instructions, equipment settings;
• to ERP: production results, produced and consumed materials;
• from ERP: production planning, order requirements;
• in CRM: tracking information;
• from CRM: complaints about the product;
• to HRM: personnel efficiency;
• from HRM: staff skills, staff availability;
• to PDES: test results;
• from PDES: Define Workflow, Define Experiments (DoE).

In many cases, Middleware Enterprise Application Integration (EAI) systems are used to exchange messages between MES and Level 4. A generic data definition, B2MML, has been defined in the ISA-95 standard to link MES to the above Level 4 systems.

Communication with level 0, 1, 2 systems

Systems operating at ISA-95 Level 2 are Supervisory Control and Data Acquisition (SCADA), Programmable Logic Controllers (PLC), Distributed Control Systems (DCS), and batch automation systems. The information flows between the MES and these process control systems are approximately the same:

• to PLC: work instructions, recipes, settings;
• from PLC: process values, alarms, corrected set points, production results.

Most MES systems include connectivity as part of their product offering. A direct link of plant equipment data is established by synchronization with. Often, data is first collected and diagnosed for real-time control in a distributed control system (DCS) or supervisory control and data acquisition (SCADA). In this case, MESs connect to these layer 2 systems to exchange data across the floors of the plant.

The industry standard for connecting to manufacturing elements is OLE for Process Control (OPC). But now the industry standard has started to move to OPC-UA. Modern OPC-UA compliant systems do not necessarily only run on Microsoft Windows, they are designed to run on GNU / Linux or other embedded systems. This reduces the cost of SCADA systems and makes them more open with reliable security.

Manufacturing companies use MES systems on the market to track raw materials along the factory path to their final state. Used correctly, this system can reduce waste, provide more accurate cost reporting, increase uptime, and reduce the need for some inventory. There are a few basic facts that everyone should know about production runtime systems.

They manage product definitions

Any experienced manager knows that even the slightest change in material can completely change the finished state of a product. A deficiency or surplus can lead to serious changes in the quality of the product. All this can lead to additional costs.

The core functions of MES systems allow you to actively track the components that make up your product. They give you the ability to assign tough parameters to your production equipment, which ultimately reduces waste and saves money.

They adequately value production resources (with some help)

As mentioned above, MES-class systems can determine the exact amount of material required to create a product, thus creating a clear product definition and maintaining product integrity. Plus, you'll always have an idea of \u200b\u200bwhat your production resources are. This category includes everything from accounting for physical materials to knowing the number of machines maintained or the availability of the manpower needed to complete a job. MES combined with APS (Advanced Planning and Scheduling) have the ability to realistically predict product completion dates for 100% of all the resources you have at hand.

They can be integrated with other production systems

Alone, production run systems often have the ability to plan production processes, but at an “infinite capacity” level and therefore can technically operate as stand-alone planning software. However, they tend to perform better when used in conjunction with other manufacturing processing software such as APS, so that ultimate constraints can also be reflected for more accurate and optimized planning.

APS defines a production schedule as a set of work orders to meet production requirements typically derived from Enterprise Resource Planning (ERP), which in turn helps to primarily use resources.

They provide analysis of production efficiency

Once a product has begun to work its way into production, MES can generate reports based on its current state. Work in progress, various historical metrics and all other performance data can be tracked using this system.

Production data tracking

When a product finally leaves the production line, MES keeps track of all the data about it and stores it for later use. Moreover, the system will not only provide you with an organized digital log of your product data, it will also be able to combine this information for future reports. Regardless of internal or external goals, you will have an ongoing update on the speed of your manufacturing processes, which ultimately helps you generate more profit.

Combined with MES it can be incredibly useful for any manager looking to increase production time and speed. Adequate resource management, production planning and product tracking will enable any company to increase production and reduce waste in both a skillful and calculated manner.

MES and APS - Together or Separately?

Before you review MES systems, you should understand how they interact with other similar tools. So, APS (Advanced Planning & Scheduling) is its own software category, such as ERP or MES. APS covers strategic, tactical and operational planning. The latter, operational use case is seen many times as the core of APS. Planning here is about working out the ultimate goal on a daily basis. Its essence is to develop possible plans to minimize excessive inventory and shorten lead times. There are many suppliers of APS systems that you can find these days.

On the other hand, the MES system executes commands and controls. There is MES software, both without any scheduling functionality and with limited functionality. In any case, the possibilities are not as extensive as in pure APS software. In the annual MES Product Review, the proportion of FCS functionality with MES software is increasing. Since it is transactional software, it is quite difficult to implement all the extensive scheduling functions in this context. Planning and forecasting requires modeling different scenarios and should not automatically affect the execution of tasks.

By tightly integrating MES and APS systems (in a closed loop), all the rich functionality of APS is used without any restrictions. If this system supports multi-site planning and a powerful Internet, the entire supply chain can be planned, executed and monitored in real time - globally without geographic constraints. For example, when you start an activity (work phase) in China, a planner in the US can see the order fulfillment in real time. Also, the seller can log into the MES / APS app over the Internet and view when the product will be shipped to the customer, without phone calls or letters.

MES and MOM: what's the difference?

Terminology can be confusing in the software industry, especially if you are just starting out. Unfortunately, this observation is true for software in industry and manufacturing. Many different systems have been used over the years, but only 2 abbreviations cause confusion:

• MES is a production execution system.
• MOM - Manufacturing Operations Management.

To understand the difference between them, it is necessary to carry out a comparative analysis of the MES systems (PDF-table) and MOM. You can highlight their similarities and differences in the course of the description.

As noted above, MES was first used by AMR in the 1990s, displacing the Computer Computing Manufacturing (CIM) system first adopted in the late 1980s. This was before many industry standards were set (such as ISA-95), and certainly much before ERP took root as the main IT backbone for most global manufacturing companies.

Many early MES systems were purpose-built in a closed loop. Because of this, they lacked the flexibility they needed to adapt to changing business needs. This resulted in many early implementations having very long calculations and often creating an implementation process that seemed to have no end. For these reasons, when introduced into production, the MES system initially earned a reputation as an expensive and risky tool that often did not achieve the original ROI goals.

At the same time, much work continued in the field of industrial automation and a number of batch-level standards (such as ISA-88 and ISA-95) emerged. They defined the term Manufacturing Operations Management (MOM). In this system, detailed activities and business processes have been defined, including production, quality, service, and inventory.

MOM development

New market conditions have led to the emergence of developers who want to rebrand and separate from the products of the past, namely from the MES. Many of them adopted the term MOM and referred to their proposals as a new solution. They offered the flexibility and scalability needed to make the system a true enterprise application, including:

• architecture based on a customizable and extensible platform;
• standardized integration with ERP;
• integration based on standards with industrial automation;
• standardized production data model;
• ample opportunities - model, visualization, optimization, updating and coordination of production business processes around the world;
• event management - the ability to collect, summarize, analyze and respond to production events in real time.

Despite this trend, previous developments have not been forgotten. The leading MES suppliers did not abandon their product. Instead, they redesigned their systems and endowed them with capabilities that match the functionality of MOM.

So what's the difference?

Today, the acronym MOM usually refers to business processes, not software. The MOM Platform (MOM Solution) designation is most often used to differentiate from older MES solutions and has the capabilities listed above.

MES is still used in most cases. It can sometimes have similar capabilities with MOM, but, unlike it, is developing at a faster pace.

MES examples

Three such systems are leading in Russia today. All of them are designed for better production management, but are designed for small-scale production. At the same time, there are differences between them.

MES-system "FOBOS" is used in medium and relatively large machine-building industries. Its main functions are in-house management and planning. It necessarily integrates with the ERP system (or "1C: Enterprise"), redirects all the received data to it.

YSB.Enterprise was created for the woodworking industry. In addition, it has some features, because of which it is more suitable for small enterprises (those where only 1C is no longer enough). The MES system has too few specific and necessary functions for full-fledged operation, but at the same time it contains additional options, including sales and accounting management.

PolyPlan has an even smaller set of MES functions, but at the same time it is presented as a tool for operational scheduling in the field of mechanical engineering (for flexible and automated production). The cost of this type of MES is the lowest.