If you have problems with planning. Part Three

Due to a more precise planning of operational, ie, calculation of the production schedule, APS, based on information on the status of supplies, inventory and availability of production capacity, said the planned launch date-release products. Emerging mismatch of the timing requirements of the current production program leads to the need for correction of target dates at the level of ERP. Planning in the MES said that MES-systems appeared over 30 years ago. Unfortunately, the authors, the general experience of which in the planning and automation of production is 45 years old, twenty years ago have not seen in the literature this abbreviation. Whatever it was, with MES-systems is more or less very clear, except one - they are constantly confused with the APS-systems. To understand what is actually MES-system, once again look at the functions of the regulated MES, whose number is exactly eleven: Condition monitoring and allocation of resources (RAS). Operational / Detailed Planning (ODS). Production supervision (DPU). Control of documents (DOC). Collecting and storing data (DCA). Human Resource Management (LM). Quality Management (QM). Management of production processes (PM). Managing maintenance and repairs (MM). Tracing the history of the product (PTG). Performance Analysis (PA). As we see in this list does not function SCM, which is central to the APS-systems. Despite the seeming at first glance, the diversity of functions of MES, we should understand that all these functions are operational in nature and not regulated by the relevant requirements of the enterprise as a whole and to one of his unit (the shop, section, unit), which is planning to work . It should also be understood that features such as document management, personnel - is the management of guild documents (purchase orders, statements, reporting, etc.) and personnel department. The main functions of MES-systems listed above are - operational and scheduling (detailed planning) and scheduling of manufacturing processes on the shop floor. These two functions define the MES-system as a system of an operational nature, aimed at creating a schedule of equipment and operational management of production processes in the shop. MES-system receives the amount of work that is either presented during ERP space-scheduling or APS-system is given in the form acceptable to the company schedule of workshops, and in the future itself is not only building a more precise schedule for the equipment, but also in online monitors their implementation. In this sense, the goal of MES-systems - not only to fulfill a given volume with the specified time frames of some orders, but to perform as best as possible in terms of economic performance shop. We have already said that APS-systems form some initial schedule of the first degree of approximation even before the start of production plans. At the same time due to the high dimensionality of the problem, do not take into account many of the technological and organizational factors. MES system is at run time to give a preliminary plan, optimize it for a number of criteria. Thus, after optimization, and building a new schedule of workshops, often due to compression of the equipment, additional reserves are found, it is possible within the planning period to fulfill additional orders. Thus, the effect is achieved by increasing the capacity of production structures. In contrast to the APS-systems, MES-systems operate on lower dimensions appointment - up to 200 machines and 10,000 operations in the planning horizon, which is usually not more than three to ten shifts. Reducing the dimension due to the fact that MES is taken into account much more technological limitations. Another difference is that the MES-systems typically do not operate with one or two criteria of a schedule, and often several dozen, which makes it possible to build a plant manager schedule according to different work situations. Only MES-systems operate so-called vector, integral criteria for the construction schedules when one criterion is going to some particular criteria. At the same controller, making the schedule may specify that he wants to see a particular schedule - reducing the duration of the calendar perform all tasks, reducing the duration of operations, setups, the release machines with a small load, etc. Efficiency of preparation and conversion schedule is also the prerogative of the MES, as conversion can be carried out with discrete in one minute. This does not mean, of course, that every minute of working will be given new tasks, but it means that all processes on the shop floor control in real time mode, and it allows to foresee all possible violations of time schedules, and take appropriate action. Figure 4. MES: Calculation of detailed production schedules at the plant. Algorithms MES-systems, although it is based, in most cases, the heuristics, but are usually much more complex and "intelligent" algorithms APS. Initially, the algorithm finds a feasible solution of MES with regard to all the limitations and the chosen criterion (private or integrated). Later, during the optimization search is the best schedule. Of course, the resulting schedule also is not optimal in the full sense, since the optimum search in such problems is always accompanied with a considerable amount of time (MES-systems build schedule for 0.1 - 5 minutes by modern technology), but obtained with this schedule, as a rule, is much closer to the optimum than the schedule constructed by APS-systems. In some cases, MES-systems can be schedules not only for machines but also for vehicle crews adjusters and other service units. No effect on any other system features such planning as a form of technology fees, planning of production with a parallel production of the required planning kit equipment (devices, a unique instrument). An important property of MES-systems is the feasibility of schedules. Built-in loop planning ERP, APS-systems make up the production schedule just in case to make in order portfolio of new products or work to correct them in real time is extremely difficult, which leads to serious problems of APS-systems in small-scale production. MES-systems in such cases, work more flexibly and efficiently, counting and adjusting the schedule for any deviation of production processes, which increases the flexibility and dynamism of production. If the schedule APS-systems are more suitable for high-volume production with the nature of production, where sharp deviations from the production program, as a rule, there is no (sustainable production), the MES-systems are essential in the short-run and custom production. In this case, if the APS-shop systems with a large amount of technological and operational information is to some extent a 'black box', the MES-systems in tasks based on the principle of calculation and adjustment of production schedules based on the actual state of production. These systems are quite sensitive to deviations in the run-time manufacturing operations, to the unexpected failure of equipment, the appearance of defects in the processing of products, and other perturbations of an internal nature. Unlike systems class ERP and APS, MES-systems are subject oriented - for mechanical engineering, woodworking, printing, etc. Therefore, they reflect the features of the fullest extent of technology-specific production processes and often include sophisticated support technological training of any type of production . Very often, MES-systems have a means of integration with CAD systems CP / ASTPP. Figure 5 shows a diagram of procedures for planning production processes, which includes but MES-system, and yet the system-level SCADA (Supervisory Control And Data Acquisition), or in the traditional abbreviation PCS - automated process control systems. As we said above, the accuracy of the schedule depends on the duration of the planning horizon and the number of jobs to make up this schedule. If the policy schedule from APS-systems can come once a week (when a new order), then for the actual workshop schedule for the current shift or day. Each operational period is characterized by its own characteristics, as mentioned above - equipment maintenance staff, temporary malfunction of equipment, etc., ie each department at the current time is characterized by its own production conditions, which may impede the strict application of the schedule issued by the APS-system. For example, when a temporary shortage of adjusters equipment, schedule for a particular plant is expedient to construct the criterion of minimum amount of time spent on changeovers. With a deficit of vehicles - the criterion of minimum time required to transport operations. Therefore, received from the APS-system in a given job shop revised MES-system. The task of MES-system - Correction of a new schedule of the equipment in accordance with the terms of private shops. MES-system operational time interval adjusts the schedule of works derived from the APS, in view of the criterion that is most relevant for the workshop at the current time. In this case the release of newly admitted to treatment DSE identified earlier APS-system for MES-systems are prescriptive. You can release these DSE before revising the schedule of workshops, but not later than its release, designed APS-system. The reason for this policy started by the APS lies in the fact that deadlines are calculated by APS, agreed with the customer and, in some cases, are present in the contract. Violation of these terms of issue may violate external to the enterprise, delivery dates of products from the customer, ie may disrupt the temporal component of the supply chain. For the company it can turn penalties. In addition to the restrictions of a temporary nature APS-system can be formulated (based on a schedule) and cost constraints character - may contain limitations on the total cost of the schedule for the production of the planned orders. As a result, the correction of the production schedule in the form detailed MES replaceable daily tasks in the workplace (OC), and prepared for all DSE operational road maps showing the dates of commencement and completion of each process step with its binding to a specific stock-no machine. Figure 5. MES: Scheme procedures for planning the production process, including SCADA. An example of shift-day job to job. Thus, MES-system in the path planning of CAM is the schedule for workshops or manufacturing site at the operational planning horizon based on the limitations of the external and internal nature of the criteria which best reflects the features department at the current time. The objectives of the MES-systems can be attributed not only a one-time scheduling of equipment for short-term planning horizon, but also his constant correction over time. In the event of failure of any OC or other object involved in the process, MES-system estimates, depending on the time of recovery of a failed piece of equipment and making deadlines DSE as an opportunity to shift to a run-time dependent DSE (with reserves time), as well as converting the entire schedule, and part of it. Thus, MES-loop system ensures the availability of automatic control of the production function taking into account the dynamically changing working conditions of private production units. Need for an unscheduled stop equipment is not always associated with reports of the operators or adjusters who receive visual information of a general nature. In some cases, marriage or manufacture of the equipment are not diagnosed visually, so in order to collect, analyze information about the quality of processes in general contour of the planning should be used CAM SCADA-systems. The objective of these hardware-software systems - collection and information on the technological process (TP) in real time, alerting in the event of TA parameters of range values ​​and the breakdown of equipment, as well - the formation of an event log and link to MES-system. Thus, through the interaction of systems and SCADA MES ensures quality control of flow and TP in the future - the timely adoption of the decision to stop the equipment, terms of scheduling. Strict functionality of the systems 'sustainability' ongoing production plans and schedules Can MES replace APS? To give a reasoned answer to this question, we note that the implementation of synchronized detailed schedules drawn up at the APS, is not simply reduced to the correction of ERP-volume plans, and to maintain their stable "stable" version: the entire production system should have a margin of stability with respect to small deviations that arise in individual departments. APS-synchronized schedule should be adjusted frequently, especially if it is not caused by external factors (violation of the terms of supply of raw materials, the emergence of new and urgent orders, etc.). And to each production unit, the company could own, "put out" resulting in him deflection required is the use of MES [5]. In the MES - on the contrary, no a priori "stability" is not supposed to production schedules, moreover, their implementation is known to be "unstable" nature (mathematics would say here that such a schedule is the so-called structurally unstable object), as suggests the possibility of surgical correction in any time at the request of the manager. Citing a certain analogy with the means of transporting bulk cargoes, ERP + APS could be compared with a good stable truck, and MES team of cyclists, which are attached to the trunk of the bag with the cargo. We can now rephrase the original question about the interchangeability of MES and APS differently: what, after all, it is better to carry the load for 100 bicycle (there have to pedal - for bike unstable) or on a stable truck? Do not hurry, dear reader, with a seemingly obvious answer, ... remember that the stable system is generally poorly managed. You should always ask themselves the question: "which way we go? And what will happen when the road suddenly ends and the path of the meet, for example, the forest? ". It is easy to predict that in this case, there is a good chance cyclists dovezti at least part of the cargo to the target ... and that's resistant to the truck, alas. Of course, in reality, not all so tragic. If planning is done for small enterprises with no more than 200 machines, then, in principle, MES and APS might be considered conditioned interchangeable. Especially when it comes to "pozakaznyh" industries. Schedules and delivery dates for this will be much more accurate, but lacks some features MES APS, for example, planning, material requirements, as MES systems are the executive and their business in the other - to fulfill the plan works, as best as possible. APS - this level of detailed planning for the entire enterprise, and MES - the level of the shop, area, division. Can we say that the MES = APS or that a system is simply a part of another (such opinions are, alas, often expressed in periodicals)? The answer clearly is negative: Of course not - despite its apparent similarity in their functionality, these systems do not match the nature of implementation they create production schedules do not match in their dynamics of stable and unstable. Those planners that form a rigid policy plans (ERP + APS) usually called Push Planning Systems - Systems, "pushing the plan," and those that quickly adjust plans during their execution, called Pull Planning Systems - Systems, "pull the plan ". Due to a more precise planning of operational, ie, calculation of the production schedule, APS, based on information on the status of supplies, inventory and availability of production capacity, said the planned launch date-release products. Emerging mismatch of the timing requirements of the current production program leads to the need for correction of target dates at the level of ERP. Planning in the MES said that MES-systems appeared over 30 years ago. Unfortunately, the authors, the general experience of which in the planning and automation of production is 45 years old, twenty years ago have not seen in the literature this abbreviation. Whatever it was, with MES-systems is more or less very clear, except one - they are constantly confused with the APS-systems. To understand what is actually MES-system, once again look at the functions of the regulated MES, whose number is exactly eleven: Condition monitoring and allocation of resources (RAS). Operational / Detailed Planning (ODS). Production supervision (DPU). Control of documents (DOC). Collecting and storing data (DCA). Human Resource Management (LM). Quality Management (QM). Management of production processes (PM). Managing maintenance and repairs (MM). Tracing the history of the product (PTG). Performance Analysis (PA). As we see in this list does not function SCM, which is central to the APS-systems. Despite the seeming at first glance, the diversity of functions of MES, we should understand that all these functions are operational in nature and not regulated by the relevant requirements of the enterprise as a whole and to one of his unit (the shop, section, unit), which is planning to work . It should also be understood that features such as document management, personnel - is the management of guild documents (purchase orders, statements, reporting, etc.) and personnel department. The main functions of MES-systems listed above are - operational and scheduling (detailed planning) and scheduling of manufacturing processes on the shop floor. These two functions define the MES-system as a system of an operational nature, aimed at creating a schedule of equipment and operational management of production processes in the shop. MES-system receives the amount of work that is either presented during ERP space-scheduling or APS-system is given in the form acceptable to the company schedule of workshops, and in the future itself is not only building a more precise schedule for the equipment, but also in online monitors their implementation. In this sense, the goal of MES-systems - not only to fulfill a given volume with the specified time frames of some orders, but to perform as best as possible in terms of economic performance shop. We have already said that APS-systems form some initial schedule of the first degree of approximation even before the start of production plans. At the same time due to the high dimensionality of the problem, do not take into account many of the technological and organizational factors. MES system is at run time to give a preliminary plan, optimize it for a number of criteria. Thus, after optimization, and building a new schedule of workshops, often due to compression of the equipment, additional reserves are found, it is possible within the planning period to fulfill additional orders. Thus, the effect is achieved by increasing the capacity of production structures. In contrast to the APS-systems, MES-systems operate on lower dimensions appointment - up to 200 machines and 10,000 operations in the planning horizon, which is usually not more than three to ten shifts. Reducing the dimension due to the fact that MES is taken into account much more technological limitations. Another difference is that the MES-systems typically do not operate with one or two criteria of a schedule, and often several dozen, which makes it possible to build a plant manager schedule according to different work situations. Only MES-systems operate so-called vector, integral criteria for the construction schedules when one criterion is going to some particular criteria. At the same controller, making the schedule may specify that he wants to see a particular schedule - reducing the duration of the calendar perform all tasks, reducing the duration of operations, setups, the release machines with a small load, etc. Efficiency of preparation and conversion schedule is also the prerogative of the MES, as conversion can be carried out with discrete in one minute. This does not mean, of course, that every minute of working will be given new tasks, but it means that all processes on the shop floor control in real time mode, and it allows to foresee all possible violations of time schedules, and take appropriate action. Figure 4. MES: Calculation of detailed production schedules at the plant. Algorithms MES-systems, although it is based, in most cases, the heuristics, but are usually much more complex and "intelligent" algorithms APS. Initially, the algorithm finds a feasible solution of MES with regard to all the limitations and the chosen criterion (private or integrated). Later, during the optimization search is the best schedule. Of course, the resulting schedule also is not optimal in the full sense, since the optimum search in such problems is always accompanied with a considerable amount of time (MES-systems build schedule for 0.1 - 5 minutes by modern technology), but obtained with this schedule, as a rule, is much closer to the optimum than the schedule constructed by APS-systems. In some cases, MES-systems can be schedules not only for machines but also for vehicle crews adjusters and other service units. No effect on any other system features such planning as a form of technology fees, planning of production with a parallel production of the required planning kit equipment (devices, a unique instrument). An important property of MES-systems is the feasibility of schedules. Built-in loop planning ERP, APS-systems make up the production schedule just in case to make in order portfolio of new products or work to correct them in real time is extremely difficult, which leads to serious problems of APS-systems in small-scale production.

MES-systems in such cases, work more flexibly and efficiently, counting and adjusting the schedule for any deviation of production processes, which increases the flexibility and dynamism of production. If the schedule APS-systems are more suitable for high-volume production with the nature of production, where sharp deviations from the production program, as a rule, there is no (sustainable production), the MES-systems are essential in the short-run and custom production. In this case, if the APS-shop systems with a large amount of technological and operational information is to some extent a 'black box', the MES-systems in tasks based on the principle of calculation and adjustment of production schedules based on the actual state of production. These systems are quite sensitive to deviations in the run-time manufacturing operations, to the unexpected failure of equipment, the appearance of defects in the processing of products, and other perturbations of an internal nature. Unlike systems class ERP and APS, MES-systems are subject oriented - for mechanical engineering, woodworking, printing, etc. Therefore, they reflect the features of the fullest extent of technology-specific production processes and often include sophisticated support technological training of any type of production . Very often, MES-systems have a means of integration with CAD systems CP / ASTPP. Figure 5 shows a diagram of procedures for planning production processes, which includes but MES-system, and yet the system-level SCADA (Supervisory Control And Data Acquisition), or in the traditional abbreviation PCS - automated process control systems. <<>> As we said above, the accuracy of the schedule depends on the duration of the planning horizon and the number of jobs to make up this schedule. If the policy schedule from APS-systems can come once a week (when a new order), then for the actual workshop schedule for the current shift or day. Each operational period is characterized by its own characteristics, as mentioned above - equipment maintenance staff, temporary malfunction of equipment, etc., ie each department at the current time is characterized by its own production conditions, which may impede the strict application of the schedule issued by the APS-system. For example, when a temporary shortage of adjusters equipment, schedule for a particular plant is expedient to construct the criterion of minimum amount of time spent on changeovers. With a deficit of vehicles - the criterion of minimum time required to transport operations. Therefore, received from the APS-system in a given job shop revised MES-system. The task of MES-system - Correction of a new schedule of the equipment in accordance with the terms of private shops. MES-system operational time interval adjusts the schedule of works derived from the APS, in view of the criterion that is most relevant for the workshop at the current time. In this case the release of newly admitted to treatment DSE identified earlier APS-system for MES-systems are prescriptive. <<>> You can release these DSE before revising the schedule of workshops, but not later than its release, designed APS-system. The reason for this policy started by the APS lies in the fact that deadlines are calculated by APS, agreed with the customer and, in some cases, are present in the contract. Violation of these terms of issue may violate external to the enterprise, delivery dates of products from the customer, ie may disrupt the temporal component of the supply chain. For the company it can turn penalties. In addition to the restrictions of a temporary nature APS-system can be formulated (based on a schedule) and cost constraints character - may contain limitations on the total cost of the schedule for the production of the planned orders. As a result, the correction of the production schedule in the form detailed MES replaceable daily tasks in the workplace (OC), and prepared for all DSE operational road maps showing the dates of commencement and completion of each process step with its binding to a specific stock-no machine. Figure 5. MES: Scheme procedures for planning the production process, including SCADA. An example of shift-day job to job. Thus, MES-system in the path planning of CAM is the schedule for workshops or manufacturing site at the operational planning horizon based on the limitations of the external and internal nature of the criteria which best reflects the features department at the current time. <<>> The objectives of the MES-systems can be attributed not only a one-time scheduling of equipment for short-term planning horizon, but also his constant correction over time. In the event of failure of any OC or other object involved in the process, MES-system estimates, depending on the time of recovery of a failed piece of equipment and making deadlines DSE as an opportunity to shift to a run-time dependent DSE (with reserves time), as well as converting the entire schedule, and part of it. Thus, MES-loop system ensures the availability of automatic control of the production function taking into account the dynamically changing working conditions of private production units. Need for an unscheduled stop equipment is not always associated with reports of the operators or adjusters who receive visual information of a general nature. In some cases, marriage or manufacture of the equipment are not diagnosed visually, so in order to collect, analyze information about the quality of processes in general contour of the planning should be used CAM SCADA-systems. The objective of these hardware-software systems - collection and information on the technological process (TP) in real time, alerting in the event of TA parameters of range values ​​and the breakdown of equipment, as well - the formation of an event log and link to MES-system. Thus, through the interaction of systems and SCADA MES ensures quality control of flow and TP in the future - the timely adoption of the decision to stop the equipment, terms of scheduling. <<>> Strict functionality of the systems 'sustainability' ongoing production plans and schedules Can MES replace APS? To give a reasoned answer to this question, we note that the implementation of synchronized detailed schedules drawn up at the APS, is not simply reduced to the correction of ERP-volume plans, and to maintain their stable "stable" version: the entire production system should have a margin of stability with respect to small deviations that arise in individual departments. APS-synchronized schedule should be adjusted frequently, especially if it is not caused by external factors (violation of the terms of supply of raw materials, the emergence of new and urgent orders, etc.). And to each production unit, the company could own, "put out" resulting in him deflection required is the use of MES [5]. In the MES - on the contrary, no a priori "stability" is not supposed to production schedules, moreover, their implementation is known to be "unstable" nature (mathematics would say here that such a schedule is the so-called structurally unstable object), as suggests the possibility of surgical correction in any time at the request of the manager. Citing a certain analogy with the means of transporting bulk cargoes, ERP + APS could be compared with a good stable truck, and MES team of cyclists, which are attached to the trunk of the bag with the cargo. <<>> We can now rephrase the original question about the interchangeability of MES and APS differently: what, after all, it is better to carry the load for 100 bicycle (there have to pedal - for bike unstable) or on a stable truck? Do not hurry, dear reader, with a seemingly obvious answer, ... remember that the stable system is generally poorly managed. You should always ask themselves the question: "which way we go? And what will happen when the road suddenly ends and the path of the meet, for example, the forest? ". It is easy to predict that in this case, there is a good chance cyclists dovezti at least part of the cargo to the target ... and that's resistant to the truck, alas. Of course, in reality, not all so tragic. If planning is done for small enterprises with no more than 200 machines, then, in principle, MES and APS might be considered conditioned interchangeable. Especially when it comes to "pozakaznyh" industries. Schedules and delivery dates for this will be much more accurate, but lacks some features MES APS, for example, planning, material requirements, as MES systems are the executive and their business in the other - to fulfill the plan works, as best as possible. APS - this level of detailed planning for the entire enterprise, and MES - the level of the shop, area, division. Can we say that the MES = APS or that a system is simply a part of another (such opinions are, alas, often expressed in periodicals)? The answer clearly is negative: Of course not - despite its apparent similarity in their functionality, these systems do not match the nature of implementation they create production schedules do not match in their dynamics of stable and unstable. <<>> Those planners that form a rigid policy plans (ERP + APS) usually called Push Planning Systems - Systems, "pushing the plan," and those that quickly adjust plans during their execution, called Pull Planning Systems - Systems, "pull the plan ". Think for a moment, whether one person budge load while pushing and pulling it? Of course not! It now becomes clear why the assertion: MESAPS. These systems are conceptually the same and are not part of each other, and be aware of this difference should be quite clear. In recent years, in pursuit of marketing bonuses, many developers began to position their products as APS or MES-solutions. In some cases this system of technological preparation of production, warehousing systems, and even conventional database. We think that the reader is by reading this article, the distinctive features of APS and MES, easily able to understand that for the product being offered, despite the marketing tricks. Thus, we see that for the company, in terms of predictability and transparency of planned release dates of production, the optimum production, the following mechanisms of planning: planning materials and resources, according to BOM (Bill of Material) for the entire range of the proposed enterprise; supply chain management, detailed operational planning and supervisory control of the implementation schedule of the equipment; This is only possible if we use all three systems - ERP, APS and MES together. <<>> ERP, APS, MES - although quite different systems with different functionality for different purposes, but they can not only get along fine, but complement each other in terms of creating a powerful enterprise planning system, covering all existing tasks. In some cases, we hear calls from the maximalist enhance the functionality of APS or MES to the level of ERP. Can this be done? In principle, it is possible. Assemble a team of developers and tell them: "In the presence of a MES (or APS). We must make it a ERP! ». All this can be done. How can raskormit cat to the size of the Caucasian guard. But then who would catch mice and keep the house? Scheme of interaction of ERP, APS, MES, SCADA system in a single production planning company. There are two basic principles of management (and planning) of large systems [2] - centralized and decentralized. In the case of a centralized planning system, for example, class ERP, should be the timetable for the entire fleet of equipment for medium enterprises as the planning horizon, and operational. Planning modules of modern ERP-systems often include APS-systems that are likely to cope with the construction schedule in the second case, the most difficult from the computational point of view. But the APS-systems have limited capacity to construct such schedules. First, the schedule constructed not only for specific units of technological equipment - machining centers (OC), for these schedules include all departmental services responsible for this OC. <<>> And if in a particular shop problems, such as the timely provision of equipment or processes changeovers transport operations (staff absenteeism and other factors), the need for further work-sharing between operators of different skills, such number of private production conditions of APS-system account can not. In most cases, APS-systems used for planning a very limited number of criteria, most of all - minimal criterion for the calendar duration of the whole complex of works on the planning horizon. But for each department, each division, in virtue of certain prevailing circumstances at a particular point, planning criteria may be different. In this case we are talking about a schedule for several departments, in some cases linked commonality of equipment or process flow, with various restrictions and criteria. In [6] considered similar problems, which are characterized by complex mathematical models for automated manufacturing systems, but currently existing APS-systems of these features are not yet supported. Second, any plan to lose accuracy is directly proportional to the magnitude of the planning horizon and the number of OC, which is planning. This means that the system of central planning must be able to rapid data collection and conversion schedules in operational mode, real-time for several hundred, sometimes thousands, and OC.