Value stream mapping algorithm. Value Stream Mapping. Alignment of agile methodologies

Seminar - training Mapping of value streams (hereinafter - Training) allows you to learn:

• quickly, simply and visually depict the state of current
  enterprise processes, material and information flows
• evaluate the main parameters of processes
• identify and analyze existing hidden losses in the system
• identify and analyze limitations ("bottlenecks") of the system
• develop a value stream map of the future (target) state of the system
• define types of instruments Lean Manufacturing,
  necessary to achieve a particular goal(s)

The training is conducted in a practical OJT (On the Job Training) format. The essence of this format is learning while doing real work.

During the preparation for the Training, the real process of the customer's company is determined, which requires any improvements. The boundaries of the process, goals and indicators of increasing its efficiency are determined. On the example of working with this process, the main practical training on mapping value streams during the Training will be built.

An important part of preparing for the value stream mapping process is setting process improvement goals. If the goals of process improvement are set clearly and specifically, have measurable indicators of the current and future (target) state of the process, then this significantly increases the efficiency of mapping, since, in fact, the main goal of value stream mapping is to build such a future state value stream map that to achieve the set goals. Properly set goals allow mapping participants to focus on the right aspects of the process and the system in which this process is included.

In this regard, after getting acquainted with the mapping methodology, before starting to build a map of the current state of the selected process, the training participants, together with the trainer, clarify and agree on the goals of its improvement in the group.

After that, a Learning Project Charter is created, which describes the current symptoms of problems or opportunities in the process, goals and measurable indicators of process improvement, boundaries and other important parameters of the project.

During this work, 2 main tasks are solved in parallel:
1) a process model of the system is built;

2) in accordance with the set goals for improving the process, existing and possible losses in the system are recorded. They are marked on the map with "red hedgehogs".

After building a map of the current state of the flow, an analysis of the root causes of the detected problems (Root Cause Analisys, RCA) is carried out. Depending on the goals set and the current situation, various RCA tools are used. Ishikawa diagram, Pareto diagram, Spaghetti diagram, cyclogram, performance analysis, bottleneck analysis, time trap analysis, 5 Why?, Shewhart charts, functional cost analysis, etc.

After identifying, assessing and structuring the root causes of problems, participants move on to finding and developing solutions to them.

When solving discovered problems, participants receive practical experience some of the Lean tools listed below:

• Flow timing (Takt time)
• Quality Embedding (Jidoka)
• Error Protection (Poka-Yoke)
• Visual Management
• Zoning
• Flow Equalization (Heijunka)
• Pull System
• Supermarkets
• Quick changeover system (SMED)
• Total Productivity Maintenance (TPM)
• Andon Dashboard & Lights
• Autonomous teams
• Cell method

Taking into account the application of some of the above tools, a value stream map of the future (target) state of the process is built.

Based on this map and the developed draft solutions, a list of measures is created to achieve the target state of the process and a plan for the implementation of improvements is created.

Value stream mapping is a fairly simple and visual graphical diagram depicting the material and information flows necessary to provide a product or service. end user. The value stream map makes it possible to immediately see the bottlenecks of the stream and, based on its analysis, identify all unproductive costs and processes, and develop an improvement plan.

Value stream mapping includes the following steps:

1. Documenting the current state map

2. Production flow analysis

3. Create a future state map

4. Develop an improvement plan

Mapping- a visualized description in a certain form of the flow (material, informational) of creating the value of a business process. Mapping is carried out in the conditions of "as is", "as it should be" and "as it will be".
With this tool, a value stream map is created that will clearly identify the time of value creation and the waste that exists in the value stream.

A creation flow map is a tool that can be used to map material and information flows during value creation. Value creation time is considered to be the time to complete the work that transforms the product so that consumers are willing to pay for it. A value stream is all the activities (value-adding and non-value-adding) needed to produce a product.

Unfortunately, practice shows that our losses amount to the lion's share process, their size reaches 80% - this is the field of activity for the Kaizen system: continuous improvement; a way of striving for excellence through the elimination of losses; proposals for eliminating losses.

Everyone knows that the needs of the consumer are constantly growing, which means that the process of improvement is also continuous, since it is aimed at transforming the needs of the consumer into specific products.

Value stream mapping includes the following steps:

Documenting the current state map

At this stage, a detailed description of the process of creating any one product (or family of products) is created, indicating all the operations and states, the required time, the number of employees, information flows, etc.

2. Production flow analysis

The purpose of building a current state map is to identify: actions that create any consumer value, and actions that do not create it.

Of the latter, some may be necessary and cannot be eliminated (for example, accounting), such activities should be optimized as much as possible, others can be reduced or optimized (for example, transportation or warehousing). To do this, the customer's requirements for the quality and properties of the product are clarified. Characteristics of the product that cannot be changed under any circumstances and characteristics that can be changed by agreement are determined. Only on the basis of such information can one accurately determine where customer value is created and where not.

Creating a Future State Map

The future state map reflects the ideal state after all the planned changes have been made. Hidden losses are also identified with a view to their subsequent elimination.

4. Development of an improvement plan

Determination of methods of transition to the future state, assignment of specific tasks, deadlines and persons responsible for implementation.

Pull-in-line production

Pull production(English pull production) - a scheme for organizing production, in which the volume of production at each production stage is determined solely by the needs of subsequent stages (ultimately - by the needs of the customer).

The ideal is “single piece flow”, i.e. the upstream supplier (or internal supplier) does not produce anything until the downstream consumer (or internal supplier) won't tell him about it. Thus, each subsequent operation "pulls" the products from the previous one.

This way of organizing work is also closely related to line balancing and thread synchronization.

Kanban system

The KANBAN system was developed and implemented for the first time in the world by Toyota.

Kanban is the Japanese word for "signal" or "card". It is a method used to pull products and materials into lean production lines. There are several variants of kanban depending on the application: starting the previous process, two-bin (single-card), multi-card, single-use kanban, etc.

KANBAN allows you to optimize the chain of planning production activities, starting from demand forecasting, planning production tasks and balancing / distributing these tasks across production capacities with optimization of their load. Optimization is understood as “not doing anything extra, not doing ahead of time, reporting an emerging need only when it is really necessary.”

The Kanban system is a production management tool that enforces just-in-time, the first principle of the Toyota Production System.
Essentially, Kanban is simple form direct communication, always where you need it. In most cases, a kanban is a piece of paper sealed in a transparent plastic bag. This sheet indicates which parts to deliver or which components to assemble.
The leaflet contains information that can be divided into three categories:
- information about the receipt of products;
- information about transportation;
- information about the product itself.

Kanban manages the flow of products and the entire production process of the company in a "pull" system. Kanban conveys information along the vertical and horizontal production hierarchy both within Toyota itself and in the system of cooperation between Toyota and partners. If the kanban system is used correctly, it is possible to synchronize and structure all stages of work.

As a result, one sheet of paper contains the following information: quantity of production, time, method, sequence or number of shipments, transit time, place of delivery, place of storage, means of transport, container, etc. If components arrive before the right time - not at exactly the right time, losses cannot be avoided. Kanban achieves just-in-time delivery because its goal is just-in-time delivery. In effect, kanban becomes the autonomous nerve of the production line.

In the Toyota production system, kanban completely avoids overproduction. As a result, there is no excess stock, and therefore, there is no need for warehouses and warehouse workers. In addition, there is no need for piles of unnecessary documents. Kanban also emphasizes the need to eliminate wastage. Its application stimulates creative thinking and initiative, and it immediately becomes clear where there are losses.
Kanban Functions:
- Provides information about the place and time of receipt and transportation of products.
- Provides information about the product itself.
- Prevents overproduction and use of excess vehicles.
- Used as a work order.
- Prevents the production of defective products by identifying at which stage defects appear.
- Detects existing problems and helps control production volumes.

The essential function of kanban is to provide information that links the previous and subsequent processes at each level.. Kanban accompanies products and is an important communication tool within the system of operational node delivery.

If the enterprise could not fully master the method of work, in which all production is organized in the form "flow", he will not be able to immediately transition to the kanban system. Other conditions include: exact "leveling" of production and full compliance with standard working methods. In order for kanban to work successfully, production stabilization and leveling are essential.

According to the first and second rules, the kanban serves as a pickup, transport, or delivery order and a production order. The third rule prohibits the purchase or production of products without a kanban. The fourth rule requires that the kanban card be attached to the product. The fifth rule dictates the condition that 100% of the products are produced without defects (that is, it contains a prohibition on sending defective products to subsequent processes). The sixth rule encourages us to reduce the number of kanbans. Half-hearted implementation of kanban leads to a lot of problems and zero benefits.
Kanban always accompanies the production and therefore becomes a production order for each process. In this way, kanban prevents overproduction, the category of the largest losses in production.
In order to confidently produce 100% defect-free products, we must put in place a system that automatically informs us of any process producing defective products. That is, a system in which the process that produces defective products is immediately fixed. In fact, this is exactly the area in which the kanban system has no equal at all.
An important feature of kanban is the ability to fine tuning within certain limits automatically. There is no detailed preliminary plan on the line, and the workers don't know which car model they will build until they read the kanban.

In general, the kanban system can be used in factories with repetitive production.. However, the repetitive nature of production may not have much of an impact if there are temporal or quantitative fluctuations in the production process. The kanban system is not applicable to the one-off production of each type of product based on periodic unpredictable orders. More than others, kanban benefits manufacturing, which deals with parts whose production requires common processes.

For the successful operation of a just-in-time production pull system, there must be a certain mechanism for controlling the movement of component elements. Kanban is currently the most effective and most widely used support mechanism for JIT. "Kanban" was developed in Japan at Toyota factories and translated from Japanese means "sign", "signal" or "card".

There are two types of kanban cards: production card and shipping card. A kanban shipping card is included on every shipping or shipping container of parts. It contains information about the number of the component element, the number of the container, the number of elements in the container. For the smooth operation of the production pull system and timely customer service, it is necessary to have certain buffer stocks of materials and products. When a product is removed from the reserve, a signal is sent to the input of a certain element of the production system that the amount of reserves has decreased. Then this element of the production system produces one item to replenish buffer stocks. The production kanban card is precisely the signal that informs production system about the need to carry out the operation for the production of the required product. It is an authorization to receive or manufacture the next batch of component parts.
A production kanban card has a number of different implementation options.
container option. Sometimes the container itself is used as a kanban card. For example, the appearance of an empty conveyor in the production area is a signal that it needs to be filled. And the number of empty conveyors
Variant of floor (table) signs. To indicate storage locations, markings (in the form of a rectangle or circle) on the floor or on the table are used. An empty rectangle indicates the need to supply this component, a filled rectangle means that these parts are not needed.
Variant of colored balls. When the number of parts is reduced to the limit level, a ball is dropped into the pipeline connecting the two sections.
Required amount circulating in manufacturing process kanban cards in proportion to the lead time, the average number of parts consumed by the next section per unit of time, and the size of the safety stock. At the same time, the safety stock should have such a level that, taking into account fluctuations in supply or demand, to ensure timely delivery of products to customers.

We thank the Press Service of NPO Saturn for providing this material.

The philosophy of Lean Manufacturing (BP) is based on the idea of ​​business as a value stream for the consumer. The outputs of processes/operations, both tangible and intangible, transferred from one process/operation to another, create a value stream. In BP, they strive to increase the speed of the value stream, ensure its continuity, uniformity and eliminate losses. The ideal value stream model from a BP point of view is the one-piece flow. Building all processes and operations in the form of a continuous value stream is a universal way to improve the efficiency of an organization.

BP tools should be used to organize the value stream and its subsequent improvement. The basic tool for organizing the value stream, which allows you to analyze the current state and describe the target state of the value stream, is the value stream map (VSC).

KPSTS is a "Scheme depicting each stage of the material and information flow necessary in order to fulfill the consumer's order" (GOST R 56020-2014).

Distinguish between current and future state KVCs.

KPSC current state

Important:

• All the data to build the current state CVSC must be collected at the same time, so it must be built in one day.
• CCPPs are always drawn by hand with a felt-tip pen on paper. All team members are directly involved in the construction.

The KPSC should reflect:

1. Customer requirements

2. Supplier Capabilities

3. Material flows

4. Information flows

5. Stocks: how many pieces and how long.

6. Information about the stages / operations of the process. For example, for machining operations:

• Time of processing
• Lot size
• Changeover time
• % of marriage
• Improvements
• Equipment Availability
• shift
• Staff
• Cycle time

7. Separation of stages/operations into value-creating and non-value-creating.

8. Calculation of the effectiveness of the value stream:

Efficiency Ratio = Value Creation (Processing) Time/Time production cycle.

The production cycle time of the entire process can be defined as the sum of the production cycle times of the steps/operations.

For a situation where stocks throughout the process greatly exceed the customer's need, the lead time will be determined by the customer's need. In this case:

Lead time (days) = Inventory (pieces)/Customer requirement (pieces/day)

9. Root causes of losses and obstacles that do not allow to provide the required level of efficiency of the value stream.

KPSC current state. Example #1(click on image to enlarge)

KPSC current state. Example #2

Target:

Identify obstacles that prevent the required level of efficiency of the value stream from being achieved.

Actions:

1. Define the object for analysis (product family, product, process).
2. Assemble a team
3. Define a leader.
4. The whole team quickly go through the flow, starting from the output of the process (shipment to the customer)
5. Determine and fix customer requirements.
6. Determine and capture supplier capabilities.
7. Determine the volume and strategy for collecting data on the process (operations, stocks, information flows and management features), prepare forms for data collection.
8. Share the entire process (objects of data collection) among team members.
9. Collect data by moving along the actual paths of material and information flows, measuring time, counting stocks and communicating with direct executors.

10. Put the collected information on paper.

12. Analyze collected data to identify losses, barriers to achieving performance targets, and opportunities for improvement. All identified causes should be applied to the CPSC.

Results:

1. Visual representation of the current state of the value stream, providing an unambiguous vision of the situation by the participants in the process.
2. The necessary information was collected to determine the target state of the process and make decisions to improve the process.

CCPP of the future state

Consider brief conclusions about the most important Lean principles that can help you start building a goal value stream map.

Sorry, this material is available in its entirety only to members of the Community of Production Managers.
You can register and get access to exclusive analytical, methodological and translated materials published on the site.

Participation also provides many additional opportunities.

Mapping is a fairly common tool in TECHNONICOL. It is used not only to analyze the entire flow, but also for individual processes.

One of the first plants to improve with value stream mapping was the Uchaly plant. In 2006, the primer value stream was chosen. Prior to mapping, we determined what is the value for the client in order to produce only what the client wants; understand the value inherent in the product from the customer's point of view and reflected in the sales price and market demand. Here is the choice of product for production, and its characteristics. It was important to understand who our client is and what this client is really willing to pay for. We discussed value in detail in the chapter on customers.

In Uchaly, mapping work was carried out under the direction of Aidar Sagadiev, Production Director. At the site, observations and measurements were made for each operation, on the basis of which a map of the current state was created.

A simple diagram depicted each stage of the flow of materials and information needed in order to fulfill the customer's order. Having identified the current value stream, the current stream was analyzed in terms of value-creating and non-value-creating activities. We saw a lot of losses to be eliminated:

1. Surplus inventory:
   • stocks of raw materials were 14 days, stocks finished products 9 days.
2. Extra transport:
   • delivery of raw materials from the warehouse to the site, the distance from the site to the warehouse of raw materials is 50 meters one way, up to 6 trips per day. Total 600 meters;
   • solvent residues were monitored once a day. The distance to the tanks is 200 meters, total 400 meters.
3. Overproduction:
   • production was carried out according to the push system.
4. Extra movement:
   • lack of a printer to print the sticker on the site. The printer was located in the production hall, the distance to which is 350 meters one way. The sticker was printed up to 3 times a day. The total movement to the shop for sticker printing was 2100 meters per shift;
   • transfer of samples for certification and quality control to the laboratory, which is located in the production workshop up to 3 times per shift. Total 2100 meters per day.
5. Over-processing:
   • packaging of the finished pallet with stretch film. Putting a pallet on a pallet wrapper up to 40 times a day, distance 6 meters, only 240 meters per shift, packing 1 pallet 1.5 minutes, only 1 hour per shift.
6. Waiting (idle):
   • waiting for the export of finished products on a pallet for packaging up to 30 minutes a day;
   • waiting for the first batch of primer to be ready - 40 minutes a day: before the start of the finished product, bitumen solidifies in the counters - warm-up time up to 3 hours.

Then we proceeded to the third stage of mapping - organizing the movement of the flow, compiled a future map of the value stream. Planned action plan:

1. Vendor area:
   • reduction of stocks of raw materials up to 6 days. Delivery of buckets according to the principle of "Milk Truck" (black and blue buckets in one car), ordering a solvent not ten days, but just in time;
   • installation of level gauges in containers with solvents with data output to the monitor in the control room (visualization of solvent residues);
   • installation of a printer at the site for printing a sticker on the spot;
   • organization of a container warehouse directly near the primer bottling shop;
   • transfer of all stocks of raw materials to a warehouse located next to the bottling shop.
2. Production area:
   • installation of heated bitumen meters at the site to prevent bitumen from solidifying;
   • preparation of one batch of primer at the end of the previous shift for bottling it at the beginning of the shift;
   • organization of a laboratory at the site for incoming control of raw materials, control technological parameters and certification of finished products;
   • conducting experiments, obtaining feedback from trading partners on the quality of delivery in the absence of 2 tapes for fastening and wrapping pallets with stretch tape;
   • creation continuous process from the moment of labeling to the packaging of the pallet;
   • creation of a supermarket stocks of packaging materials.
3. Shipping area:
   • reduction of stocks of finished products up to 4 days;
   • installation of limiters at the ramp for quick installation machines for loading and unloading;
   • installation of ramp and warehouse number indicators on the territory;
   • placement of the loading ramp closer to the GP storage area.

Mapped the future value stream.

Figure 1. Current and Future Value Stream Maps, Uchaly Primer and Cold Mastics Production Area.

The primer and cold mastics production area has undergone significant changes. After the implementation of the measures, the production cycle time was reduced to 14 days, the value creation time a year after the initial mapping in 2007 was 95 seconds, in 2008 after the implementation of the flow - 36 seconds. Turnover of finished goods increased from 9.78 times a year in 2006 to 17 times a year in 2007. It was possible to double labor productivity at the site, reduce stocks of raw materials by 8.6%, and stocks of finished products - by 70.5%. Production and storage areas were reduced by more than 30%.

When building a value stream map, we used the recommendations of the authors of the book “Learn to see business processes. The practice of building value stream maps”:

Work on improving the entire flow and individual processes in the primer and cold mastics production flow at the plant continues to this day, although, of course, the results are no longer as impressive as the first time. The process of continuous improvement goes in a spiral. Each turn results in a less and less significant reduction in losses and an increasingly closely related and efficient work. At some point, continuous improvement turns into a series of small incremental improvements.

Gradually, mapping became an integral part of the work of most of the company's divisions. Hand-drawn maps began to be transferred to a computer. The mapping process itself has become more formalized. Forms of documents appeared for compiling flow maps, annual plans flow improvement and flow analysis. If more than one division of the company was involved in the flow, they began to get together to work on improving the end-to-end flow. Figures 3-6 show work to improve the flow of roofing roll materials that were sold through the company's distribution centers. Accordingly, two divisions of TECHNONICOL are involved in the flow here: the Ryazan plant for the production of bituminous roofing materials Technoflex and the regional distribution center of the company, from where a whole range of the Company's goods and building materials third party manufacturers.

Figure 2. Map of the current value creation stream for the Roll Materials product group, Ryazan

Figure 3. Map of the future value stream for the Roll Materials product group, Ryazan

Figure 4. Annual plan for improving the value stream for the roll materials product group, Ryazan

Figure 5. Analysis of the value stream for the product group "Roll materials", Ryazan

Process improvement

Mapping is a fairly common tool in TECHNONICOL. It is used not only to analyze the entire flow, but also for individual processes.

Figures 6 and 7 provide an example of using a mapping tool to visualize, analyze and then improve the process of shipping finished products to a customer.

Figure 6. Current map of the process of shipment of GP to the client, customer service department, Ryazan

On the current map, in yellow shading, we see the places of subsequent improvements, which allowed us to reduce the number of client-side decisions and increase the efficiency of the process, allowing us to achieve the result reflected on the future map.

Figure 7. Future map of the process of shipment of the GP to the client, customer service department, Ryazan

1 Primer is one of the high-quality and affordable compositions on the modern construction market for strong adhesion of glued materials to rough, porous and dusty surfaces.

2 Rother M. Learn to see business processes. Value Stream Mapping Practice / Mike Rother, John Shook; Per. from English. - M. : Alpina Business Books: CBSD, Business Skills Development Center, 2005. - 144 p.

The work of value stream mapping usually starts with goal setting. Once a goal is identified, it is formulated, measured, and visualized. Leader along with working group must understand what they should strive for and what they are working for.

After the goal is formulated, the preparation stage begins. On the this stage all costs for the performance of work to achieve the goal should be taken into account.

At the stage of choosing a product, according to which the KPSC will be formed, the boundaries of the process under consideration are determined and, depending on the goals set, priorities are set among a wide variety of products.

The formation of the current state CVSC (“as is”) is one of the longest stages of mapping. At this stage, all steps of the process from entry to exit are considered in detail, important parameters of each step are noted and recorded. Team members must go through the entire stream in question and see with their own eyes the gradual transformation of the product. The management system and related logistics are also considered in detail.

The analysis stage is the processing of the collected information to determine the impact points that have the greatest impact on the entire process under consideration. The main areas of analysis are: analysis of flow problems in terms of the degree of influence and potential, analysis of the loading of process stages (operations) per takt time, analysis of the quality of manufactured products and logistic analysis. At this stage of the analysis, it may be necessary to collect additional information or clarify individual data. Some stages of the process may require a more detailed analysis using other Lean tools and methods, so the quality of the work at this stage is very important, since all further work depends on it.

The next step in shaping the future state of the CVSC is to compare the flow opportunities identified in the analysis with the necessary requirements for maximum efficiency process. The ideal state of the process is formed with ideal parameters each stage with information flows and logistics routes and the target state that is needed at the moment. At the same stage, a preliminary economic evaluation: Determine the one-time and ongoing benefit of transforming a stream into a target state.

Development of a transition plan to the target state is a stage of step-by-step planning of the sequence and timing of real actions that are necessary to transition to a new flow state without harming the external Customer. The changes relate to both material and information flows, as well as changes to existing regulatory documentation to eliminate contradictions or duplications.

The following steps, such as the implementation and stabilization phase, are no longer directly relevant to the application of the CVSC tool, as The purpose of mapping as a tool is to detect losses and determine the most efficient flow alignment possible. In this situation, it must be understood that any system that is tampered with needs some time (depending on the degree of tampering and the quality of the system) in order to start working stably. During the implementation of the measures, constant monitoring of compliance with the changes should be ensured. New standards should be tested in practice, staff should be trained, informed and gradually get used to the changes.

Table 2.1 Mapping algorithm

	Name	Consequences of skipping a stage
	goal setting	Decrease in efficiency due to waste of resources, decrease in the level of motivation of the working group.
	Training	Reduced efficiency due to the lack of rhythm of work, slowing down the process
	Product selection (product families)	Decrease in efficiency due to the impact on insignificant parts of the flow (work without applying the Pareto rule)
	Formation of KPSC "as is"	Disruption of work
	CVSC analysis	Disruption of work
	Formation of the KPSC “as it will be”	Disruption of work
	Development of a transition plan	Disruption of work
	Next steps (implementation)	Disruption of work

Despite the fact that not all stages of the mapping algorithm lead to a breakdown in work (non-receipt or nulling of results and the pointlessness of continuing work), each of them affects the efficiency of the work as a whole. This can be seen in table 2.1. The loss of work performance efficiency at each stage by 10%, no matter how it is measured, purely from a mathematical point of view, at the eighth stage (implementation of measures), instead of 100% efficiency, it is already only 47.83% (0.97 * 100% \u003d 47 .83%). Since each stage contains several more small steps that contain potential opportunities for making mistakes and temptations for ignoring them, performing all the required steps as accurately and in detail as possible, you can increase the potential efficiency of the target state of the process, and therefore, we strive for the maximum possible final result.

Formation of the current state

The first step in shaping the current state of the CVSC is to define the process itself. It is necessary to answer the questions: “what is the name of the process that is being considered” and “where are the boundaries of this process?” The formulation of the name of the process is deliberately singled out as a separate sub-stage in the formation of the current state. The wording of the name of the process will determine its content, boundaries, and, consequently, all further work. The name of the process should have a clear and unambiguous wording that reflects the essence of the process, visualized as the heading of the current state CVSC.

Next, it is necessary to determine the inputs and outputs of the process under consideration, its duration, that is, it is necessary to determine the boundaries within which the selected flow will be considered. In organization-wide mapping, boundaries may be external Suppliers and Customers, unless otherwise decided by the goals and decision of managers. On the scale of a separate production or workshop, some internal and external Suppliers and Customers can be defined by the boundaries: adjacent workshops, production facilities, etc. The definition of boundaries is necessary for a clear direction of work, since in the process of mapping one can get carried away by considering information that is not interesting and unnecessary to achieve the goal. Thus, by spending a minimum of time on marking the boundaries of the process under consideration, visualizing these boundaries (schematically, or along with the name of the process), you can insure yourself against unnecessary and unproductive work. In various cases, there may be several Suppliers and Customers. For example, when the manufacture of a product requires several types of raw materials, materials or blanks supplied by different suppliers, regardless of whether they are internal or external, or when one product is shipped to several Customers. In practice, it is more convenient to start with the outputs of the process, and then, moving back along the technological chain, determine the inputs of the process. After determining the inputs and outputs and when the boundaries appeared, you can proceed to the definition of the stages of the process under consideration, that is, its internal content.

Each product has its own technology and goes through certain production stages (operations) in the process of its transformation into a product. At the stage of determining the stages of the process, team members visualize the overall content of the process, indicating which operations (process stages) the product goes through in the process of its transformation into a finished product.

Here I consider it necessary to explain why two terms are used: operation and process step. KPSC, depending on the process under consideration, can have several levels. One stage of the large-scale process in CVSC can be represented as a smaller-scale CVCC, in which the input and output will be adjacent to the considered (previous and subsequent) stages of the large-scale process

The next step is to define the parameters of the process steps. Among the variety of possible parameters, it is necessary to choose those that need to be studied at the analysis stage. In this situation, it is necessary to ask the following questions: “what are the goals and objectives?” and “what parameters can be used to influence them?” Certain parameters of the process steps are visualized under each step (figure 2.1).

In this example, the main indicators are:

• · The cycle time of an operation in which an operation is performed on one unit of product, for example, one bicycle frame is welded or one set of wheels is assembled. Use uniform units and measurement scales, they will greatly simplify the task. Value creation time (Vst), pg.u. the very useful time for which the Customer is ready to pay, during which the product is modified or acquires the properties necessary for the Customer. For example, in the case of frame welding, the value creation time is the time of simultaneous contact between the two pieces to be welded and the welding electrode (assuming electric welding is being performed). All other actions (preparation, shifting, fastening, etc.) are losses.
• · Number of workers involved in each operation. Here we consider only those workers who are involved in the product transformation and value-adding process. Unless otherwise specified by the tasks, we do not take into account management and maintenance personnel, such as foremen and cleaners, work distributors, etc., as well as logistics personnel who move the product between stages of the process.
• Changeover time is the time required to switch from one type of product to another, in our example, these are bicycle models that have different production technologies and designs.
• · The percentage of correctable and irreparable marriage, i.e. the proportion of parts leaving the stream under consideration either forever or moving to the beginning of one of the previous stages of the process.

Figure 2.1. Process Step Options

The next step is bypassing the process or Go-Look-See (go, look and notice). This is one of the principles of Lean, which means solving problems at the point of origin, as well as making decisions from the point of value creation, i.e. when a problem arises, it is necessary to go and look, getting the most reliable information. With regard to mapping, the main goals of Go-Look-See are to see the stages of product transformation with your own eyes, to collect the maximum amount of reliable data about the process in question. According to the principles of Lean, when a problem arises, it is necessary to go to the place of its discovery, assess the scale of the problem, the possible causes of its occurrence, and make decisions based on up-to-date information received directly on the spot, and not from the words of subordinates transmitted along the chain.

Separately, it is worth highlighting the construction of the "spaghetti" diagram. When working with CVSC, a "spaghetti" diagram is a diagram of the movement of a product (in some cases, a person, materials, etc.) applied to the layout of a site (factory, workshop, workplace, etc.). The name corresponds to the lines on the layout, similar to a plate of "spaghetti". This diagram is necessary for a visual representation of the route and distance that the product in question does in the process of its transformation into a finished product. It visually shows the losses during transportation due to suboptimal routes, location of delivery points or operations and allows you to measure these losses by calculating the distance. To build a spaghetti diagram, you need a layout or diagram of the area where the process in question physically operates. For plant-scale mapping, this will be the plant layout; for site-scale mapping, it will be the site layout. At the stage of determining the stages of the process (operations), the actual locations of the corresponding stages of the process are marked on the layout based on the expert opinion of the team members. They will need to be numbered accordingly in order to be linked to the KPSC. During the Go-Look-See, the planning data is checked for compliance with reality, in case of discrepancy, adjustments are made.

The general algorithm for constructing the current state CVSC looks like in the block diagram (Figure 2.2). The results of the work, as can be seen from the diagram, are two complete documents: the spaghetti diagram and the current state KPSC.

Figure 2.2 General algorithm for constructing the current state CVSC

CVSC analysis

The analysis stage is the most important in terms of using the potential of the team members, its knowledge and skills in dealing with various methods and analysis tools. There are a lot of methods of analysis, as well as the tools used, but in relation to the value stream, I want to consider the classic direction of analysis - the analysis of "flow bottlenecks".

The analysis of bottlenecks is necessary to develop measures to bring the flow of traffic in accordance with the needs of the Customer. The most efficient in terms economic indicators- this is work in accordance with the needs of the Customer, when we produce only what is needed in right time. Such a system assumes the absence of overproduction, excess stocks in the flow and other losses arising from this. An indicator that characterizes the rhythm of production in accordance with the needs of the Customer is the takt time. Takt time (Tt) is always a calculated value, which is the ratio of the time available for production (net time for work without lunches and regulated breaks) and the Customer's need for products for a certain period of time. In other words, takt time is the period of time after which the Customer wants to receive a unit of production. Perfectly synchronized production (lossless production), in which each process step (operation) runs under takt time (for example, the cycle time of an operation is equal to or slightly less than takt time).

Takt time \u003d Available time for work, sec / Need for products, pcs

Figure 2.3 General bottleneck analysis algorithm

The general flow bottleneck analysis algorithm is shown in Figure 2.3. As already mentioned, the analysis begins with the calculation of the takt time. The next step is to refine the cycle time of the process steps. Operation cycle time (hereinafter referred to as cycle time) - the period of time during which each process (operation) produces a unit of output, includes a small fraction of the value creation time and many losses. I want to draw attention to the difference between the takt time and the cycle time. Takt time is a period of time for the release of a unit of a product, idealized for the needs of the Customer. . The cycle time is the actual period, taking into account all losses and factors negatively affecting production. The essence of the step of clarifying the cycle time is to check the data of each stage of the process (operation) for compliance with the above formulation, because small deviations in this data can not only provoke the appearance of losses, but also completely desynchronize the work of the thread, making further work useless.

The construction of the Yamazumi diagram (load diagram) is a visual representation of the load of each stage of the process (operation) in the form of bar charts (Figure 2.4). To build a Yamazumi d., three elements must be known: the calculated takt time, the cycle time of each process step (operation), and the execution sequence of the process step (operation). Time is plotted along the y-axis, all stages of the process (operation) are listed in order along the abscissa. The column height of each operation corresponds to its cycle time. The takt time is visualized as a horizontal line at the corresponding level. The sequence of execution of a process step (operation) consists of adding value and losses, reflected in green and red colors, respectively. At this step, the actual state of the diagram is built based on the collected data. Due to the specifics of the processes under consideration, some of their stages (operations) can be rebalanced. Rebalancing refers to redistributing the load of operations to align it with the takt time. When rebalancing, the sequence changes within the process stage (operation) and the transfer of their components from more loaded stages to less (3 and 4). Rebalancing is carried out by team members (cross-functional groups), which must include a person who knows about the features of the technology, and a production foreman who directly knows the specifics of the balancing operations, as well as representatives who understand the requirements of the Customer and the features of all considered stages of the process (operations). For example, if you measure the execution of several simple sequential operations, you can find (in most cases it happens) that the cycle time of some operations differs by an order of magnitude. In terms of flow, this means that someone does not have time to process products - operations with a long cycle time, and someone produces excess stock, or works "sloppy" - operations with a shorter cycle time. Rebalancing using visualization in the form of D. Yamazumi allows you to redistribute individual actions between operations, of course, if technology, security and common sense thus minimizing overall costs. In the example shown in the figure, as a result of the work carried out, activities that do not create value were optimized, such as, for example, No. 5 in operation 1 and No. 4 in operation 2 (Figure 2.5). To load all the operations under the measure in the above example, the actions from operation 4 (No. 5,3) and operation 3 (No. 6,7) were separated into an additional fifth operation. If the takt time were longer (the Line was higher), balancing would be optimal by moving various actions between operations, i.e. without any additional operation.

Figure 2.4 Diagram of Yamazumi Figure 2.5. Rebalancing with Visualization

Rebalanced operations should not be loaded exactly at takt time (Bt = Tt), there should always be a small reserve of 5-10% depending on the stability of the process in question in case of unforeseen problems and in order to avoid overloading workers. In fact, there is a choice: under what value of time to balance operations, since it is obvious that a small reserve is a deliberately inherent risk of disrupting the task, and a large reserve discourages staff. As a rule, the transfer of individual actions is carried out between neighboring operations, and the resulting slack (if any) should remain on the last operation (closest to the customer) to give greater flexibility in solving emerging problems.

The result of the splitting is a list of "bottlenecks" and Pareto d. (Figure 2.6 and Table 2.2), reflecting the main risks of the flow. The Pareto diagram is built on the basis of deviations of the cycle time of operations from the takt time, thus it is possible to single out the main list of operations that most strongly constrain the entire flow under consideration. Assessing the fluctuations in the customer's needs over a certain period of time, for example, the last year, we can assume that during the next year the takt time can vary within 10 - 1596 of the average value. This means that by optimizing the operations under consideration, it should be possible, if necessary, to reload them to meet the increased demand. It is necessary to understand all the limitations and anticipate the risks before they develop into problems. This is the step "determining the potential by Vc". Perhaps the list of operations that need to be “embroidered” will increase.

Figure 2.6 Pareto chart of flow bottleneck analysis

Table 2.2 List of flow bottlenecks

Future state of the OPC

It should be noted right away that it is necessary to distinguish between the concepts of "future state", "ideal state" and "target state".

The ideal state of the KPSC is a flow map built in accordance with the principles of the formation of the future state and as close as possible to the ideal. This is usually the maximum number of operations aligned to the takt time, lined up according to the pull system, or a stream of single products with a minimum product transit time. In practice, the ideal state of the KPSC is limited only by the imagination of the team members, as there is no limit to perfection.

The target state of the CVSC is a flow map improved in comparison with the current state to a certain extent, corresponding to the goals and objectives set. Looking at the improvement scale, the target state is between current and ideal.

The future state is usually general concept transformed after improvements to the current state of the CVSC, the term is used in relation to both the ideal and the target state of the flow. It turns out that in order to achieve goals, you must first form an ideal picture, stepping over goals, opportunities, existing negative paradigms, and then return to what is needed at the moment.

The proposed algorithm for the formation of KPSC is shown in the block diagram (Figure 2.7).

The first point in the algorithm is the clarification of the requirements of the Customer”, here it is necessary to recall the goals formulated at the beginning of the work. Well, if they were not forgotten throughout the course of the entire work. Before building a new state of the process (flow), it is necessary to remember who the Customer is (whether internal or external) and what he expects from the new state of the process, how can you anticipate his desires? At this step, there is a certain restructuring of the thinking of the team members to the needs of the Customer and the beginning of idealized thinking.

Figure.2.7 Algorithm for CVSC formation

The next step - teaching the principles of shaping the future state - requires special attention. The team leader and team members should review these principles in detail before proceeding. After mastering the principles, the team members step by step form the ideal state of the process stages, starting from the Customer (from the end of the technological chain) to the Supplier (the beginning of the technological chain), consistently applying the principles to each stage of the process (operation). It is important to check and make sure that all steps of the process are considered.

Further, the focus is on two documents: the ideal state CSC and the ideal state spaghetti diagram. Here, new flow parameters and physical movements of the product are determined, continuous brainstorming is carried out until the ideas are completely finished. The stage of formation of an ideal state is as complicated as it is necessary. Now I will try to explain. The ideal state is a kind of imaginary picture of the alignment of the considered flow without losses, the most optimal and effective way from the group's point of view. The so-called ideality is limited only by the height of the flight of thought. At this stage, it is necessary to discard all mental restrictions on the possibility of implementing this or that improvement, concentrate on the principles of forming the future state of the flow and think about how to implement them, and not what prevents it. This is very important, because in practice the formation of the ideal state very often ends with the formation of the target state, because group members cannot overcome that barrier of pressing problems that prevents them from going beyond reality and fantasizing about how it could still be. It is in such cases that the participation of an external expert is very important. Thus, the target state of the KPSC and the spaghetti diagram are formed. The only point is the definition of information flows, which should be the final step in the formation of the target state CVSC. After building the pull logistics according to the principle of “determining the operation that sets the rhythm”, information flows are determined, i.e. frequency, methods, roles and places when sending signals about the need to manufacture a certain number of products and receiving feedback.

Step-by-step formation of KPSC

It is necessary to form the CPS of an ideal state from the last operations of the technological chain: from the end of the stream. The campaign involves the consistent application of the principles of the formation of the future state (those related to material flows) for each operation. The word “step-by-step” in the title means that until the brainstorming session on a particular stage of the process is fully completed, the group does not begin to consider the next one. The step-by-step state formation algorithm can be represented as the following block diagram (Figure 2.8). As already stated, all stages of the process (operation) are considered in turn, the possibility of excluding or combining with another, usually neighboring operation of the flow, is determined. This step involves determining the need for this operation and the possibility of physically combining operations adjacent to the KPSC to build a continuous flow. The physical combination or location of two operations in close proximity will allow you to build a continuous flow of single products (without the presence of work in progress), on the FIFO principle (first in first out or “first in, first out”). In other words, help ensure an immediate transition finished product from the previous operation to the next, reducing the time for transportation and inter-operational stocks.

Fig.2.8 Algorithm for generating a step-by-step state

Where possible, it is necessary to form a cell, which is also a kind of one-piece flow, and align the loading of operations under the previously calculated time. If it is not possible to balance the load (due to the peculiarities of the technology or equipment), the focus of work is directed to the principle of "management of the pull system": the methods, methods and frequency of delivery of products between operations are determined, stocks are calculated, and the procedure for signaling the need for manufacturing is determined. the required number of items. The ideal state is visualized step by step as a new CVCC. After the formation of the ideal state, the group forms the target state, the one that is required at the present time.

 

It might be useful to read:

• Radiation: impact on humans and its consequences;
• Arts and Crafts Download Presentation on Arts and Crafts;
• Presentation on the topic "Addition and subtraction of polynomials" Addition and subtraction of polynomials presentation;
• Radiation: impact on humans and its consequences;
• Open lesson "capacitors" Energy of a charged capacitor application of capacitors presentation;
• Presentation on the topic "Nikolai Nosov "Live Hat"";
• Presentation "globe" presentation for a lesson on the world around on the topic;
• Presentation on the topic: "A walk in kindergarten;