Manufacturing Execution System
A manufacturing execution system ( MES ) is a process-related level of a multi-layer manufacturing management system. The German term production control system is often used synonymously. The MES distinguishes itself from similarly effective systems for production planning , the so-called ERP systems (Enterprise Resource Planning), by the direct connection to the distributed systems of process automation and enables the management , guidance , control or monitoring of production in real time . This includes classic data acquisition and preparations as production data acquisition (PDA), machine data collection (MDE) and personal data collection , but also all other processes that have a timely impact on the manufacturing / production process.
The term MES generally refers to a multi-layered overall system that covers the business reporting and production planning levels of the company's ERP and the actual manufacturing or production process in the manufacturing or automation level. In particular, the MES is used for the continuously controlling implementation ( execution ) of an existing and valid plan and for feedback from the process.
definition
The term production control stands for the comprehensive description of this task. MES map the detailed processes for the respective process of the specific production task while tying up resources on an IT system . Some commonalities from the various industry solutions can be seen that a basic MES must offer users in the company:
- a production schedule for each product (before the start of the process)
- a production planning system (for a planning period)
- a production process (for a product)
- resource planning (for a product)
- the current allocation of resources (in parallel with the process)
- local production control centers in manufacturing
In addition, MES often offer the following options:
- Management of means of production (resources) in the assignment to products
- Ensuring planned maintenance work that occupies resources without allowing production
- Acquisition of production and product data for statistical evaluation
- Interfaces to materials management and construction
- Reporting on commercial order processing
Other terms used
The term production control system (or production control system) is used very branch-specifically in German. A basic distinction is made between production control technology (piece goods production) and process control technology (process technology production). Depending on the point of view, other terms are also preferred. Computer scientists , especially business informatics , speak of CIM in this context . In industrial practice, however, this term has a reputation for low efficiency, since expectations in this context increased in the 1980s and 1990s, for example
- the runtime in the feedback of the operating data
- because of the lack of quick intervention options in the event of bottlenecks in resources
- because of the awkwardness of the operating data acquisition aids
- because of the large variety of interfaces
often remained unfulfilled.
As an alternative to the term MES, there is also the term CPM (Collaborative Production Management), which refers to a "collaborative" collaboration between production and the areas peripheral to production, such as B. Purchasing, Procurement and Controlling.
In some industries, e.g. For example, in the opencast mines of RWE-Power, operations management systems are also used in this context. Systems for managing the maintenance of production plants are subsumed here.
In the last few years, the term MES has increasingly prevailed over other terms in German texts.
tasks
The scope of an MES can be subdivided into three areas of responsibility: Production data acquisition (BDE), locking and traceability. BDE data refer to the machine. They are made available at all times, regardless of whether the machine is in production or not. The trigger can be an alarm or a change of state. In contrast, there is the locking. It is triggered by the product to be produced, which is in front of the machine or has been newly inserted. The purpose of the interlock is to ensure that all parameters are set correctly by the machine before production / processing begins. Traceability completes the processing of a product; The process parameters and the processed material are stored in this data.
The PDC data should essentially contribute to increasing the throughput in the entire technical order processing through rapid repeated optimization . So it is not primarily business models that are newly developed or improved, but the technical process itself forms the model, the state of which is continuously monitored and visualized . For this purpose, special key figures ( KPI ) are determined and evaluated. I.a. are these sizes like:
- BDE
- Waiting times and free buffers
- Processing time and transfer buffer
- Machine utilization
- Machine availability
- Product yield
- Locking
- Automation of armaments
- Checking the setup parameters
- Traceability
- Proof of production
- Detection of production defects
- Increase in quality
- Limitation on recall
- Insurance reasons
In VDMA standard sheet 66412 (draft May 2009) approx. 20 MES indicators are published, including an explanation of the derivation formula and the area of application. An international working group (WG9 in ISO / TC184 / SC5) has also been set up on this subject. The MES should improve the overall competitiveness of the company.
integration
MES in a software architecture are typically below the ERP level. This means that planning for production is often created on the ERP level and then the production plan is transferred to the MES level. The MES level, on the other hand, reports the processing status of the individual orders to the ERP level so that it can be used there for logistical control - for example, planning the next periods.
The reasons for the separation between ERP and MES are the different business and technical requirements as well as the typical cycle times for revising an existing plan. While an ERP system administers the entire company and is supposed to enable logistical optimization on an aggregated level across plants and lines, which usually does not require online up-to-date status, an MES monitors a local production line and has to record technical parameters online in addition to the required logistical control data that are not of interest for an ERP. In this sense, MES are the executive arm of an ERP.
Implementations
As a product, MES appears both as a complete package and in individual components, in the form of software, possibly supplemented by hardware for data acquisition and control. As with automation, the problem of connecting the individual components to an effective whole also arises here. Larger providers deliver “everything from a single source”, while the smaller providers specialize in individual areas of the MES (e.g. quality assurance ).
Neutral consulting firms differentiate the MES provider market into special categories:
1. MES, which are usually adapted and expanded on a project-specific basis to customer requirements. Often these are smaller providers who come into play when it comes to special requirements that the larger standard systems do not easily cover.
2. MES that come from the world of automation technology. They are characterized by a high degree of integration into the process and automation technology, production data acquisition (PDA) and machine data collection (MDE), the NC program distribution ( DNC ), material flow control and possibly in the tool management (tool management). They often offer options for visualizing the current situation in production.
3. MES, which basically can be assigned to the supply chain management systems (SCM). They serve to coordinate several production areas along the value creation process, also across plant and company boundaries. Here, the boundaries between advanced planning and scheduling systems (APS), which i. d. Usually form the basis of an SCM solution for cross-location coordination. The essential feature is the planning and simulation based on optimized mathematical algorithms from Operations Research , but less an actual operational connection to the manufacturing processes. Here the boundaries between MES and pure planning tools are blurred.
4. A related category to the SCM / APS systems are tools that cover planning optimization as a special MES sub-area, but actually do not represent an integrated MES because they lack essential functions.
5. An important category are systems that have their origin in individual MES areas, e.g. For example: - in quality management, - in personnel time recording and administration, or - in production data recording, but depending on the stage of development, complete standard MES with numerous integrated modules have been created. T. take up market-leading positions.
However, a clear delimitation and simple classification of the systems is not possible, especially since the boundaries are becoming increasingly blurred due to the providers' convergence strategies.
The solutions of the large ERP providers in the area of production control are only adaptable to a limited extent, have longer feedback times and a less granular resolution of the observation. For example, the modules for detailed planning and machine data acquisition (MDE) do not have the same range of functions as with specialist providers. For this reason, MES are implemented as additional components between the process and the ERP modules. The data exchange between the systems is preferably carried out via IETF - RFC interfaces in real time , but can also be exchanged asynchronously using ASCII files. In newer solutions, MES↔ERP web services are used for communication.
MES are primarily used in flexible variant and customer order production. The real-time automatic production control with the help of an MES can develop its full strength there due to the complexity of the variant production.
Resource planning
Are the detailed planning modules with additional resource information - such as B. Employee matrices, i.e. the number of available employees within a shift as well as their training, are stored, so up-to-date production plans can be generated that take into account the actual employee capacity and their skills.
standardization
The term MES is kept transparent in Germany by the VDI guideline 5600 and the NAMUR worksheet NA 94.
The standardization committee of the automation industry ISA has published several standards on the subject of MES. Reference is made here to ISA S95 for the integration of MES into the application architecture of a company and to ISA S88 for the modeling of processes (status concept etc.) of an MES. The ISA works with industry services such as the Mesa Associates, Inc. together.
The ISA is doing fundamental work on standardization in this area in the SP95 project . JWG5, a joint working group of IEC / SC65E and ISO / TC184 / SC5, is transferring the corresponding specifications into the ISO / IEC 62264 standard series (Enterprise-control system integration, Part 1: Models and terminology). Parts 1 to 3 have already been published, parts 4 and 5 are currently being worked on.
In the ISO, the TC184, industrial automation and integration, deals with this topic, although the targeted classification of various activities in the models of ISO / IEC 62264 has only just begun.
The SC4 of the TC184 includes the standardization of data structures and content for product modeling. It is one of the largest bodies in the ISO and has become known for the extensive series of standards ISO 10303, STEP , Standard for Exchange of Product Model Data.
The SC5 of the TC184 deals with the architecture, communication and framework specifications for integration in industrial automation. The following working groups are currently active here:
- WG1: Modeling of companies, e.g. B. ISO 15704 and ISO 19440
- WG4: Description of software properties (for interoperability and cataloging), ISO 16100
- WG5: Framework for Profiles for Integration, ISO 15745
- WG6: Service interfaces for device integration (see also ASAM eV ), ISO 20242
- WG7: Diagnosis and maintenance, specific reference to ISO / IEC 62264
- WG9: Key figures for MES (or MOM), ISO 22400-2
- JWG8: Joint WG of SC4 and SC5, data structures and content of manufacturing processes, ISO 15531
- JWG5: Joint WG of SC5 and IEC / SC65E, transfer of ISA S95 to ISO / IEC 62264
In Germany, the topic is dealt with in DIN NA 060-30-05, Mechanical Engineering Standards Committee (NAM) , Industrial Automation Department, Architecture and Communication Committee, the German mirror committee for ISO TC184 / SC5. Target objects are technical criteria for differentiating MES from other applications. The international standards cited above are used as a basis, where appropriate.
The translation and maintenance of IEC 62264 is carried out in Germany by the DKE in the control technology department, system aspects, K 931. This work is carried out by the above DIN committee used.
Association activities
Internationally, the associations MESA and Operations and Maintenance Information Open System Alliance MIMOSA deal with the topic of MES.
In the German-speaking area, MES wants DACH. Association offer a platform for users and MES manufacturers and promote the exchange of information and networking. With the establishment of the "Universal Machine Connectivity for MES" (UMCM) interface concept, the association is striving for uniform MES functions and bidirectional interfaces.
In Germany, the VDI , the ZVEI , the VDMA and the NAMUR are active on the subject of MES, with the VDMA massively supporting the work of DIN NA 060-30-05 (see standardization).
The MES technical committee of the VDI is working hard to create uniform definitions and to protect the term MES from marketing-driven "erosion". In particular, the requirements of MES users should also be taken into account and systematically evaluated.
For this purpose, the VDI 5600 guideline was developed, which describes the tasks and benefits of MES in an application-oriented form. It is primarily aimed at potential users in manufacturing companies, e.g. B. Production manager or work planner and describes ten typical MES tasks:
- Task 1: detailed planning and fine control
- Task 2: resource management
- Task 3: material management
- Task 4: Human resource management
- Task 5: data acquisition
- Task 6: performance analysis
- Task 7: Quality management
- Task 8: information management
- Task 9: Energy management
- Task 10: order management
The main focus of the guideline is on the presentation of the benefits that MES users can expect. In addition, the guideline of the VDI competence field information technology shows which production processes and sub-processes are supported by MES. It enables a well-founded overview of the mode of action and the potential of MES without having to familiarize yourself with the information technology details of such systems. It can serve as a neutral description of the possible "scope of services" and as a basis for creating requirement specifications for MES.
See also
- Process control system
- B2MML
- Open Platform Communications
- Workshop control
- Production control station
- PPS system
- Control room
Web links
Individual evidence
- ↑ [1]
- ^ ISA
- ↑ TC 184 / SC5
- ↑ TC 184
- ^ Industrial automation systems, Requirements for enterprise-reference architectures and methodologies
- ^ Enterprise integration, Constructs for enterprise modeling
- ↑ Industrial automation systems and integration, Manufacturing software capability profiling for interoperability ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ↑ Industrial automation systems and integration, Open systems application integration framework ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ↑ automation systems and integration, Service interface for testing applications ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ↑ Valid ISO / IEC 62264 standards ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ↑ Key performance indicators for manufacturing operations management ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ↑ Industrial automation systems and integration- Industrial manufacturing management data ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ↑ Valid ISO / IEC 62264 standards ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ↑ NAM
- ↑ Archived copy ( Memento of the original from January 4, 2011 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ MIMOSA
- ↑ MES DACH. Association
- ↑ Table of contents of VDI guideline 5600 sheet 1 from October 2016. (PDF) VDI, accessed on August 16, 2017 (German, /, English).
