Coursework: Materials management systems. The essence of logistics as the science of managing resource flows

The main purpose of this system is to build a production cycle schedule that would show which processes should be started at what point in time; the movement of what quantity of raw materials and semi-finished products at what point in time is required for the functioning of production. In order to create a production cycle schedule (also called an MRP schedule), the following information must be available: a master production schedule, which indicates the volume finished products for each item, manufactured in each period of time; list of materials specifications, which lists the materials and components included in the finished product unit; inventory accounting documentation (how much inventory of each item is in the warehouse).
The master production schedule is a table compiled from customer orders or by forecasting the requirements for goods produced by our plant. Depending on the

The specifics of the enterprise’s operation may assign different planning horizons. In general, it is necessary to have a production plan for at least the next month in order for the MRP system to function. An example of a basic production schedule is given in table. 3.1.

Month	May 2014			June 2014			July 2014			August 2014			September 2014
Decade	1	2	3	1	2	3	1	2	3	1	2	3	1	2	3
product HOS 339852		40						60					39
product HOS 339854					111					95					14
product HVG 432906	6							35

Table 3.1
According to the main production schedule, the enterprise must produce units of the product XOS 339854 in the third ten days of September, 39 units of the product XOS 339852 in the first ten days of September, etc.
A complete specification of materials is a diagram that shows in detail all the components that make up the finished product. Finished products are designated level 0, components have level numbers 1, 2, and so on, right down to the materials that the organization always purchases from suppliers. The number of items at this level can be hundreds and thousands of units. An example of a graphical representation of a “dining table” product specification is shown in Fig. 3.8.
In addition to the graphical method of displaying product specifications, it is possible to use a tabular presentation. Although there is some loss of visibility, the tabular presentation is more useful if the operation of the MRP system is computerized. An example of a tabular presentation of the product specification “dining table” is given in table. 3.2.
Inventory accounting documentation is a table that indicates the balances of materials and semi-finished products used in

manufacturing of the product in question. This table can be a certificate from an automated inventory management system, or it can be compiled manually when preparing a production schedule for a batch of products.

Table 3.2

Let's consider an example of drawing up a schedule for the need for materials for the manufacture of 100 units of product A (100 units is the batch size of the finished product, which we obtained from the main production schedule). According to the specification, product A consists of one product B and three products C. Product C, in turn, consists of four products D and one product E. The production time for each product and the amount of inventory for them are given in table. 3.3.
Table 3.3
Data for drawing up an MRP schedule First of all, it is necessary to draw up a production cycle schedule (also called a “production cycle schedule”). It is useful for determining the cycle time for producing a unit of finished product and for visually identifying the start and end points of each process. The cycle schedule for the production of product A is shown in Fig. 3.9.

As can be seen from the cycle schedule, the process of manufacturing a unit of product A takes 7 days. Please note that on the second day the manufacturing processes of products B and C must be completed and the process of assembling the finished product (product A) must begin. Such process interface points will be very useful for us in the future, as they will allow us to check the correctness of the MRP schedule. So, for example, on schedule of production of this product on the second day, counting from the end of the cycle, work on processes A, B and C should be planned. Other processes on this day are not provided for by the cycle schedule, therefore, they should not be present in the schedule on this day.
The materials requirement schedule is a table in which the rows represent products, and the columns represent the dates on which the product manufacturing processes should be started or completed. In the simplest version of the operation of the MRP system, three lines are allocated for each product: BP - gross requirement (the number of products that must be transferred to the next operation), stock (the available stock of products of this item) and an order for production (the number of products that should be produced to meet gross demand taking into account available stocks). In table Figure 3.4 shows a fragment of the MRP schedule.
Table 3.4
Fragment of the MRP schedule

		Time
		0	1	2	3	4	5	6	7
A	BP								100
	stock	10
	/>order						90
B	BP						90
	stock	30
	order					60
C	BP						270
	stock	0
	order				270

According to the cyclic schedule, the duration of the production cycle is 7 days. Therefore, in the MRP schedule, we must provide one column for each of the seven days, plus another column, zero, in order to start the production cycle. The gross requirement for item A is 100 units and occurs on the 7th day. On this day, the production of batch A of products is completed and they must be transferred to the finished goods warehouse or directly to the customer. There are 10 units of item A in inventory, therefore we must plan to produce 90 units (90 = 100-10). We must start production on the 5th day, since the need arises on the 7th day and the assembly of product A from products B and C according to the table. 3.3 takes two days.
In order for us to begin assembling product A on the 5th day, we must have the required number of products B and C available by this day, since it is from these products, according to the specification, that product A is assembled. Therefore, the need for products B and C appear on the 5th day and amount to 90 units of items B (one item B costs one item B; we collect 90 items A) and 270 items C (one item A costs three items C; we collect 90 items A ). The order for the production of products B must be placed on the 4th day (the need for products B arises on the 5th day; the production of product B lasts one day). The order for product B is 60 units (demand - 90 units; available stock - 30 units; 60 = 90-30). The order for the production of product C must be placed on the 3rd day (the need for these products arose on the 5th day; production duration is 2 days) and will amount to 270 units (there are no products C in stock, so the order quantity for production coincides with the gross need). Please note that on the 5th day (the second day, counting from the end) the processes associated with products A, B and C appear, as we determined earlier using the cyclic schedule (see p. 79).
The dates and volumes of orders for the remaining products required for the manufacture of batch A of products are determined in the same way. The complete MRP schedule is given in table. 3.5.
Table 3.5
MRP schedule

		Time
		0	1	2	3	4	5	6	7
	BP								100
A	stock	10
	order						90
	BP		/>				90
B	stock	30
	order					60	gt;-
	BP						270
C	stock	0
	order				270
	BP				1080
D	stock	10
	order	1070
	BP				270
E	stock	10
	order			260

If you draw up a separate MRP schedule for each batch of products, day zero must be filled in - one or more processes must be scheduled to start on this day. In our case, on day zero, production of 1070 units of product D begins.
The compiled MRP schedule shows on what day which processes should begin and which should be completed. With its help, you can plan the work of repair, transport and various support units. For example, on the MRP schedule (see Table 3.5) the first and sixth days are “empty”, i.e. these days there is no movement of work in progress from one stage to another. Consequently, the transport division of the enterprise these days can be reoriented to other projects, or can carry out Maintenance technology. One more example. The equipment used to manufacture products D is occupied according to our schedule from day zero to day three inclusive. Therefore, starting from fourth day, we can load this area with some other tasks.
Typically, the MRP model is used in assembly work or in a continuous production method, when there is a dependent demand for items of labor. The use of an MRP system allows you to reduce the volume of raw material inventories, increases the speed of inventory turnover, and makes it possible to increase the degree of equipment utilization. The main disadvantages of this system include the inability to quickly respond to signals from the external environment, as well as the need to organize a clear exchange of information.
Another drawback is that the MRP model does not take into account equipment performance limitations. If it takes 2 days to produce one unit of product C, we are forced to assume that the production of 270 units of product C will also take the same two days. In mass production, the solution is to produce components in batches and determine the production time of a batch of products, but this approach significantly complicates the calculations.
Let's consider another example of using the MRP system - building a schedule for the need for materials, taking into account production defects. Suppose we need to create an MRP schedule for the production of 300 units of product A. Each product A consists of two products B, three products C and one product D. Product D, in turn, consists of two products E. The duration of the operations, The scrap rate for each operation and product inventories are given in table. 3.6.
For simplicity, we assume that defects appear only in the production of new products. Products in stock have passed quality control and are free of defects. To determine the duration of the finished product manufacturing cycle, we will draw up a cycle schedule. It is shown in Fig. 3.10.

Data for drawing up the MRP schedule


		IN

			WITH	A
	E
		D

7

Rice. 3.10. Cycle schedule for the production of product A

The production cycle of product A lasts 7 days. Let's start building the MRP schedule (Table 3.7). Since in this example we take into account only manufacturing defects, each product will have four lines: gross requirement, stock, additional order,
designed to compensate for defects, and the final order for production. An additional order can be calculated in two ways. If the products in stock have passed quality control and do not contain defects, formula (3.1) is applied.
DZ = (BP-Zap)^ , (3.1)
where DZ is an additional order, units;
BP - gross demand, units;
Zap - stocks of products of this name, units; d is the scrap rate for this operation, share.
MRP schedule

		Time
		0	1	2	3	4	5	6	7
	BP								300
A	stock	0
A	marriage (5%)						15
	order						315		/>
	BP						630
B	stock	400
B	marriage (10%)			23
	order			253
	BP						945
C	stock	120
C	marriage (10%)					83
	order					908
	BP						315
D	stock	80
D	marriage (10%)				24
	order				259
	BP				518
E	stock	280
E	marriage (5%)	12
	order	250

In the event that the products in stock have not passed quality control and may contain defects, the additional order is calculated using formula (3.2).
DZ = BP-d (3.2)
If the values obtained from formulas (3.1) and (3.2) turn out to be fractional, they should be rounded to the nearest big side.
Obviously, in the conditions of our problem we should use formula (3.1).
The final order will be calculated using formula (3.3).
IZ = BP-Zap + DZ, (3.3)
where IZ is the final order, units.
Thus, when taking into account possible errors in the execution of operations, the volume of orders for the production of components increases. If

Product specification includes many levels, the impact of defects will lead to an increase in order volume exponentially.

If you ask yourself what concept, term. category in logistics are the most important, then among the candidates for this place of honor will undoubtedly be “ flow" or " material flow" Indeed, the object of study of logistics (if we talk about it as a science) is flows, especially material flows. Undoubtedly, the accompanying information and financial flows also play a fundamental role. And there are many other types of flows in logistics: labor, service, energy. Therefore, it is worth analyzing in detail the concept of flow in logistics, giving its definitions, and offering a classification.

Flow in logistics: concept, features, types

As already mentioned, the object of study of logistics science is flow. And the subject of study is stream optimization, optimal control them.

Flow processes are observed in any logistics system (from a small company to a giant transnational corporation), flows surround us in Everyday life. Transportation of cargo, movement of parts along the factory conveyor, shipment commercial products, people in the subway, current in wires - all these are one or another type of flow.

It’s interesting that there is a separate science that studies management material flows within the enterprise – rochrematics.

This is not the same as logistics! Moreover, the sphere of interests of logistics is much broader: in addition to material flows, information, financial, and service flows are studied; At the same time, logistics goes far beyond the scope of an individual company, considering it in conjunction with other participants in business relations, other generators and consumers of material flows (competitors, clients, government).

The classification of enterprise material flows is very extensive. Here are the most important types of material flows organizations:

1. According to the direction of movement:

input stream– comes into the logistics system from the external environment (for example, the purchase of components by a plant);
output stream– on the contrary, it emanates into the external environment from logistics system(for example, shipping a completed order).

2. In relation to the logistics system:

internal flow– flows inside it (for example, moving a workpiece around the workshop during its processing);
external flow– moves in the external environment (for example, transporting goods from a warehouse to stores). But external flows do not include any flows occurring outside the logistics system, but only those to which the organization has something to do!

3. According to the degree of complexity of the internal structure:

simple(differentiated, single-product) flow – consists of homogeneous objects (for example, a flow of identical blanks for stamping);
difficult(integrated, multi-product) flow - includes heterogeneous dissimilar objects (for example, a flow of various radio parts: resistors, capacitors, transistors).

4. By degree of certainty:

deterministic(definite) flow - all its characteristics are known or predetermined (for example, a regulated process for releasing finished products from the enterprise’s warehouse);
stochastic(uncertain) flow - at least one of its parameters is unknown or cannot be controlled, being a random variable (for example, it is impossible to accurately calculate the number of cars moving on a section of the highway at a certain point in time).

5. By degree of continuity:

continuous flow - over a certain period of time (minute, hour, day) a fixed and/or non-zero number of objects pass through a certain point in the flow trajectory (for example, a continuously moving conveyor with milk tetrapacks);
discrete(intermittent) flow - objects along the trajectory of the flow move at intervals, pauses, interruptions (for example, deliveries of raw materials at a certain interval, say, once a month).

6. According to the consistency of the load (i.e., according to the degree of its density, thickness, hardness) in the flow, its physical and mechanical properties:

solid packaged piece– the cargo is transported without a protective shell, or in boxes, packages, containers, bottles, bags; and in both cases it can be accurately counted piece by piece (for example, bricks on wooden pallets);
solid bulk– this is a dry bulk cargo, usually of mineral origin, transported without any container, in bulk, and with a tendency to sinter or caking (examples of bulk cargo: quartz sand, mineral salt, coal);
solid bulk– also transported without packaging in specially equipped vehicles(special containers, bunker-type cars), has flowability (examples of bulk cargo: crushed stone, gravel, grain);
liquid, liquid cargo- transported in tanks or specialized liquid vessels (for example, milk, kerosene, oil);
gaseous cargo– transported in closed containers, tanks; often taking precautions (since gas can be explosive and flammable). Examples: butane, oxygen, methane.

It is worth noting that the above classification can in some cases be applied not only to material flows, but also to other types of flows of the logistics system: information, financial, human.

Also, a number of researchers highlight various types of material flows by: variety of composition (single-product, multi-product), industry (industrial, commercial, agricultural, construction, municipal), volume of cargo (small, medium, large, and also mass), compatibility of flows, stability, specific gravity load (lightweight, heavy), degree of danger, magnitude of flow variability (stationary, non-stationary), uniformity and rhythm of movement, etc.

Information flow in logistics and its types

IN modern world information has great value, turning into a valuable resource in itself. Each material flow is invariably accompanied by an information flow. Thus, cargo transportation is accompanied by paperwork, route approval, broadcast of GPS data, etc. That is, the management of related information flows.

At the same time, the information flow in an organization can flow as relatively synchronously(that is, in parallel, simultaneously) with the material flow that gave birth to it, so carry leading or lagging character.

Information flow (information flow) are messages (in any form, from oral to electronic) generated by the initial material flow and intended to carry out control functions.

Information flows in logistics can be similarly divided into incoming and outgoing, internal and external.

In addition, it is worth mentioning classification of information flows:

1. By type of storage media:

streams on traditional paper media (notes, documents, letters);
streams on digital media (flash cards, CDs);
streams electronic communication channels (computer and telephone networks).

2. According to the purpose of the information:

directive- transmit orders and instructions; play an executive function;
normative and reference- norms, standards, various reference Information;
accounting and analytical- control parameters, accounting information, analytical data;
auxiliary threads- everything else, information is useful, but not of paramount importance.

3. According to the information exchange mode:

online streams- data is transmitted through telecommunication networks in real time;
offline streams- data is transmitted offline, verbally or through paper documents, letters.

4. By method of information transmission:

postal service;
by courier in hand;
by telephone or fax;
by email(e-mail);
Internet messengers.

5. According to the degree of openness (secrecy):

open streams (available to everyone);
closed flows (available only within the company, division);
secret(confidential) streams.

Financial flows and their classification

Financial flows play a major role in the activities of any commercial (and non-profit too) organization. Without financial resources It is impossible to purchase components and raw materials, pay hired labor, provide transportation, and much more.

Managing a company's financial flows is one of the basic tasks of company management.

Financial flow (financial flow) is the directed movement of financial assets circulating within the logistics system (warehouse, factory, bank), as well as between it and external environment, and interconnected with material or other flows.

Don't confuse cash flow with cash flow (cash flow). These are different concepts that have various areas applications.

The financial flows of an enterprise, like all previous types, can also be divided into internal and external (depending on their direction), and into incoming and outgoing (according to the place of flow). But in addition, we can describe several types of flows in logistics that are inherent specifically to financial flows:

1. By purpose:

purchasing(purchase of raw materials and materials);
labor(workers' compensation);
investment(purchase of securities);
commodity(Shopping retail network for implementation).

2. In the direction of economic relations:

horizontal flows- circulation of finances between same-level links;
vertical flows- circulation of finances between links located at different levels of the hierarchy.

3. According to the calculation form:

monetary– cash flow;
information and financial– non-cash transfers;
accounting and financial– occur during the formation of material costs in the production process.

Service and other types of flows in logistics

Material flows are traditionally considered the main ones in logistics. Information and financial flows are closely interconnected with them. But the variety of flows in logistics does not end there! For example, service flows or, in other words, service flows are often distinguished.

Service thread– this is a certain volume of services provided to clients over a specific period of time.

Freight flows can be considered a special type of material flow.

Freight flow(freight traffic) is the volume of cargo transported over a certain period (usually one year), along a specific route in separate units.

We can distinguish other types of flows in logistics: transport, customer flows, labor, application flows, energy.

Very often, the material and the auxiliary flows accompanying it form a kind of integral entity, a system that has a certain structure and stability. We can say that this is an integrated logistics flow.

Galyautdinov R.R.

2 MATERIAL FLOW MANAGEMENT SYSTEMS

A materials flow management system is understood as an organizational mechanism for the formation of planning and regulation of material flows within the framework of an intra-production logistics system.

A flow is a collection of objects, perceived as a single whole, existing as a process over a certain time interval and measured in absolute units over a certain period. Flow parameters are parameters that characterize the ongoing process. The main parameters characterizing the flow are: its initial and final points, the trajectory of movement, the length of the path (a measure of the trajectory), the speed and time of movement, intermediate points, and intensity.

Based on the nature of the constituent objects, the following types of flows are distinguished: material, transport, energy, cash, information, human, military, etc., but for logistics, of the above, material, information and financial are of interest.

The concept of material flow is key in logistics. Material flows are formed as a result of transportation, warehousing and other material operations with raw materials, semi-finished products and finished products - from the primary source of raw materials to the final consumer. Material flows can flow between different enterprises or within one enterprise.

Material flow is a product (in the form of cargo, parts, inventory items), considered in the process of applying various logistics (transportation, warehousing, etc.) and (or) technological (machining, assembly, etc.) operations to it and attributed to a certain time interval. The material flow does not pass over a time interval, but at a given point in time, into a material stock.

The material flow is characterized by a certain set of parameters:

nomenclature, assortment and quantity of products;

overall characteristics (volume, area, linear dimensions);

weight characteristics (total weight, gross weight, net weight);

physical and chemical characteristics of the cargo;

characteristics of the container (packaging);

terms of purchase and sale agreements (transfer of ownership, supply);

terms of transportation and insurance;

financial (cost) characteristics;

conditions for performing other physical distribution operations related to the movement of products, etc.

The material flow on its way from the primary source of raw materials to the final consumer passes through a number of production links. Material flow management at this stage has its own specifics and is called production logistics.

The tasks of production logistics relate to the management of material flows within enterprises that create material goods or providing such material services, such as storage, packaging, hanging, stacking, etc.

Logistics systems considered by production logistics are called intra-production logistics systems. These include: industrial enterprise; wholesale enterprise, having storage facilities; cargo hub; hub seaport, etc. Intra-industrial logistics systems can be considered at the macro and micro levels.

At the macro level, intra-production logistics systems act as elements of macro-logistics systems. They set the rhythm of operation of these systems and are sources of material flows. Ability to adapt macrologistics systems to changes environment is largely determined by the ability of the intra-production logistics systems included in them to quickly change the quality and quantitative composition output material flow, i.e. the range and quantity of products produced. Qualitative flexibility of intra-production logistics systems can be ensured due to the presence of a universal service personnel and flexible manufacturing. Quantitative flexibility is also provided in various ways. For example, in some Japanese enterprises, the core staff makes up no more than 20% of the maximum number of employees. The remaining 80% are temporary workers. Moreover, up to 50% of the number of temporary workers are women and pensioners. Thus, with a staff of 200 people, the company can assign up to 1,000 people to fulfill an order at any time. Reserve work force supplemented by an adequate reserve of equipment.

At the micro level, intra-production logistics systems represent a number of subsystems that are in relationships and connections with each other, forming a certain integrity and unity. These subsystems: purchasing, warehouses, inventories, production services, transport, information, sales and personnel, ensure the entry of material flow into the system, passage within it and exit from the system. In accordance with the concept of logistics, the construction of intra-production logistics systems should ensure the possibility of constant coordination and mutual adjustment of plans and actions of supply, production and sales links within the enterprise.

When demand exceeds supply, we can confidently assume that a batch of products manufactured taking into account market conditions will be sold. Therefore, the goal of maximum equipment utilization takes priority. Moreover, the larger the batch produced, the lower the unit cost of the product will be. The task of implementation is not in the foreground.

The situation changes with the arrival of buyer “dictation” on the market. The task of selling the manufactured product in a competitive environment comes first. The volatility and unpredictability of market demand makes it impractical to create and maintain large inventories. At the same time, the manufacturer no longer has the right to miss a single order. Hence the need for flexible production facilities that can quickly respond with production to emerging demand.

Reducing costs in a competitive environment is achieved not by increasing the size of produced batches and other extensive measures, but by the logistics organization of both individual production and the entire commodity distribution system as a whole.

There are several materials management systems:

MRP – materials requirements planning;

DRP – resource allocation planning;

JIT – management of material and information flows based on the “just in time” principle;

KANBAN – information support operational management material flows based on the “just in time” principle;

OPT – optimized production technology.

2.1 Push systemmaterial flow management.

Push system is a production organization system in which objects of labor arriving at a production site are not ordered directly by this site from the previous technological link. The material flow is “pushed” to the recipient according to a command received by the transmitting link from the central production management system (Fig. 1)

Control system

Raw materials warehouse

Assembly shop

Legend:

Material flow, Information flow

Rice. 1. Schematic diagram of a pushing material flow management system within the framework of an intra-production logistics system

Push models of management and flows are characteristic of traditional methods of organizing production. The possibility of their use for the logistics organization of production has appeared in connection with the massive spread of computer technology. These systems, the first developments of which date back to the 60s, made it possible to coordinate and quickly adjust the plans and actions of all divisions of the enterprise - supply, production and sales, taking into account constant changes in real time.

Push systems capable of linking a complex production mechanism into a single whole using microelectronics and maximizing the use of workers and equipment in production. However, in the event of a sharp change in demand, the use of a “push” system leads to the creation of excess inventory and “overstocking” due to the lack of the ability to “reschedule” production for each stage. The parameters of the material flow “pushed” to the site are optimal to the extent that the control system is able to take into account and evaluate all the factors influencing the production situation at this site. However, the more factors for each of the numerous sections of the enterprise the control system must take into account, the more advanced and expensive its software, information and technical support should be.

2.2 Pulling systemmaterial flow management.

Another option is based on a fundamentally different way of managing material flow. It's called "pulling system" and is a production organization system in which parts and semi-finished products are supplied to the subsequent technological operation from the previous one as needed.

Here, the central control system does not interfere with the exchange of material flows between different parts of the enterprise and does not set current production tasks for them. The production program of an individual technological link is determined by the order size of the subsequent link. The central control system poses a task only to the final link of the production technological chain. Pulling system involves maintaining a minimum level of inventory at each stage of production and movement of the order from the next section to the previous one. The subsequent section orders material in accordance with the rate and time of consumption of its products. The work schedule is established only for the consumer site (shop). The manufacturing site does not have a specific schedule or plan and works in accordance with the received order. In this way, only those parts that are actually needed are manufactured and only when the need arises.

D
In order to understand the mechanism of operation of the traction system, let's consider an example (Fig. 2).

Rice. 2 Pull material flow management system within an intra-production logistics system

Let's say a company receives an order to produce 10 units of products. The control system transmits this order to the assembly shop. The assembly shop, to fulfill the order, requests 10 parts from workshop No. 1. Having transferred 10 parts from its stock, workshop No. 1, in order to replenish the stock, orders ten blanks from workshop No. 2. In turn, workshop No. 2, having transferred 10 blanks, orders materials from the raw materials warehouse for the manufacture of the transferred quantity, also with the aim of restoring the stock. Thus, the material note is “stretched out” by each subsequent link. Moreover, the personnel of a separate workshop are able to take into account many more specific factors that determine the size of the optimal order than a central control system could do.

2.3 Logistics conceptR.P.

One of the most popular logistics concepts in the world, on the basis of which a large number of logistics systems have been developed and operate, is the concept of “Requirements/resource planning” - RP (“requirements/resource planning”).

Basic systems based on the RP concept in production and supply are the MRP I / MRP II systems - “Materials/manufacturing requirements / resource planning” (Material requirements planning systems / production resource planning systems) and in distribution (allocation) - DRP I / DRP II - “Distribution requirements/resource planning” (Product/resource distribution planning systems). MRP and DRP are push control systems. Although the RP logistics concept itself was formulated quite a long time ago (since the mid-1950s), it was only with the advent of high-speed computers that it was put into practice, and the revolution in microprocessor and information technologies stimulated the rapid growth of various applications of RP systems in business.

Based on the nature of the constituent objects, the following types of flows are distinguished: material, transport, energy, Money, information, human, military, etc., but for logistics, of the above, material, information and financial are of interest.

Material flow is a product (in the form of cargo, parts, inventory items), considered in the process of applying various logistics (transportation, warehousing, etc.) and (or) technological (machining, assembly, etc.) operations to it and attributed to a certain time interval. The material flow is not on a time interval, but in this moment time goes into material stock.

The material flow is characterized by a certain set of parameters:

· nomenclature, assortment and quantity of products;
· overall characteristics (volume, area, linear dimensions);
· weight characteristics (total weight, gross weight, net weight);
· physical and chemical characteristics of the cargo;
· characteristics of the container (packaging);
· terms of purchase and sale agreements (transfer of ownership, delivery);
· conditions of transportation and insurance;
· financial (cost) characteristics;
· conditions for performing other physical distribution operations related to the movement of products, etc.

The tasks of production logistics concern the management of material flows within enterprises that create material goods or provide material services such as storage, packaging, hanging, stacking, etc.

Logistics systems considered by production logistics are called intra-production logistics systems. These include: industrial enterprise; a wholesale enterprise with warehouse facilities; cargo hub; hub seaport, etc. Intra-industrial logistics systems can be considered at the macro and micro levels.

At the macro level, intra-production logistics systems act as elements of macro-logistics systems. They set the rhythm of operation of these systems and are sources of material flows. The ability to adapt macrologistics systems to environmental changes is largely determined by the ability of their intra-production logistics systems to quickly change the qualitative and quantitative composition of the output material flow, i.e., the range and quantity of products produced. High-quality flexibility of intra-production logistics systems can be achieved through the availability of universal service personnel and flexible production. Quantitative flexibility is also provided different ways. For example, in some Japanese enterprises, the core staff makes up no more than 20% of the maximum number of employees. The remaining 80% are temporary workers. Moreover, up to 50% of the number of temporary workers are women and pensioners. Thus, with a staff of 200 people, the company can assign up to 1,000 people to fulfill an order at any time. The labor reserve is complemented by an adequate reserve of equipment.

There are several materials management systems:

· MRP - materials requirements planning;
· DRP - resource allocation planning;
· JIT - management of material and information flows based on the “just in time” principle;
· KANBAN - information support for operational management of material flows on the “just in time” principle;
· OPT - optimized production technology.

Materials management systems

There are several materials management systems:

MRP – materials requirements planning;

DRP – resource allocation planning;

JIT – management of material and information flows according to the “just in time” principle;

KANBAN – information support for operational management of material flows based on the “just in time” principle;

OPT – optimized production technology.

Material requirements planning- This automated system planning production needs for the necessary material resources. MRP allows for priority planning of order fulfillment in real time, taking into account emerging deviations from planned targets, as well as ongoing regulation and control of inventories. The main goals of MRP are: guaranteed satisfaction of the need for material resources, maintaining the minimum possible level of inventories; increasing the accuracy of production planning, supplies and material purchases.

Resource Allocation Planning can be characterized as an automated system for managing outgoing goods. She happens to be mirror image MRP uses the same logic, tools and methods. The main functions of the system include: supply and inventory planning at various levels of the distribution chain (central - peripheral warehouses), information support for product distribution, as well as transportation planning. The main production schedule is formed in accordance with independent demand data (demand forecast). Thus, DRP allows you to link the functions of production and sales of products, as well as optimize logistics costs by reducing transport costs and distribution costs.

MRP and DRP are push-type systems.

JIT an integrated material and information flow management system that represents the production process and associated supply and sales as a single continuous production flow. Material flow management in a unified system is carried out on the basis of reverse scheduling. The manufacturer does not have a complete plan and work schedule; he is closely connected not with the general, but with the specific order of the consumer of this product and optimizes his work within the limits of this order. For all departments, only average plans (for a month) are developed, and their detailing by decades (days, hours) is carried out by the direct performers of the work, taking into account the deadlines for delivery of parts (assembly units) and the volume of the task received.

KANBAN serves as information support operational management of material flows based on the “just in time” principle. The “KANBAN” application card contains all the necessary information about consumer requests. As a rule, such information includes: name and part code; specification of containers indicating their type and the number of parts placed in them; name of the manufacturing site and consumer site of the product; delivery time, determined taking into account the duration of production of the part. Each previous section in the technological chain operates in accordance with the received order indicated in the “KANBAN” card. Monitoring the progress of production is carried out by registering cards in circulation.

ORT belongs to the class of “pull” micrologistics systems that integrate supply and production processes. The main operating principle of this system is to identify production process so-called “bottlenecks” or critical resources. Essentially, ORT is a computerized version of KANBAN, with the difference that the ORT system prevents the emergence of bottlenecks in the supply-production logistics network, and the KANBAN system allows you to effectively eliminate bottlenecks that have already arisen. Critical resources that influence the efficiency of the logistics system can be stocks of raw materials and supplies, the size of work in progress, manufacturing technology, personnel, etc. Enterprises using the ORT system do not strive to maximize the load on personnel performing non-critical operations, as this causes undesirable growth of work in progress inventories. The effectiveness of the ORT system from a logistics point of view is to increase production output, reduce production and transport costs, and reduce work in progress inventories.