Alignment of production by quantity and type of products We have already talked about losses in production facilities when they are set up for peak demand. But even with increased capacity, if only one product is produced, it is quite possible to develop

CREATE ASSOCIATED PROCESS THREAD

IDEAL - SINGLE PRODUCT FLOW

Taiichi Ohno taught that the ideal is a flow of single products. A correct answer on a school exam gets an A. The correct answer is one-piece flow. Coming out to master Lean you just need to create a flow of single items. What could be simpler? In fact, Ohno taught that creating a one-piece flow is extremely difficult and its use is not always practical. He said:

In 1947, we lined up the machines in parallel lines, and in some places arranged them in the shape of an L, and tried to put one worker on three or four machines according to the processing sequence. Although there was no talk of increasing the pace of work or overtime, the workers desperately resisted. The machine operators did not like that the new layout required them to combine professions... In addition, other problems were discovered. Once it became clear what kind of problems these were, I was able to decide in which direction to move. Although I was young and energetic, I decided not to insist on immediate radical changes, but be patient.

It learned to be patient and careful in reducing waste while always moving toward one-piece flow, also called “continuous flow.” Products go through sequential processing steps, waiting times between operations and product movement paths are minimized - all this ensures maximum efficiency. Flow reduces overall production cycle time, speeds up cash flow and leads to improved quality. However, Ohno understood that the flow of single products was very vulnerable.

Attempts to create continuous flow lead to the identification of problems that impede flow. Essentially, to create a thread, have to solve problems, and this leads to reduction of losses. We often compare production to a ship sailing through a sea full of underwater rocks. High water levels, like high reserves, hide rocks, i.e. problems. But if the level of water and reserves drops, the ship can crash in no time, hitting the rocks. Most operations have many pitfalls, and it is natural that we try to keep enough inventory, which hides problems.

Ohno discovered that if inventory levels were reduced, problems came to the surface. People have to solve them, because otherwise the production system will stop. This is not bad as long as the problems are not too severe and people are able to optimize the process, preventing the same problems from occurring again. Ohno also realized that this required a minimum level of system stability, otherwise reducing inventory would only lead to a loss of productivity, as we saw in Chapter 4.

Linking two or more processes into a continuous flow makes any problem more acute and requires immediate resolution. A connected flow across an entire enterprise means that unless the problem is effectively resolved, it will stop. All enterprise, and maybe several enterprises. Think about how important equipment availability, labor availability, and supplies are if thousands of people are forced to stop working in the event of a malfunction! This happens on Toyotas from time to time. Since all processes are connected together, a problem with one of the main components leads to the shutdown of the entire plant within a few hours. I

Many organizations believe that such production stoppages are unacceptable. Those who stopped production have a direct route to the labor exchange. However, Toyota views this situation as an opportunity to identify weak spots system, overcome identified deficiencies and strengthen the system as a whole. Such a paradoxical way of thinking baffles those who are accustomed to thinking only about financial results. The Toyota Way suggests that viewing failures as opportunities for improvement can significantly improve long-term results. The traditional way of thinking, on the contrary, is based on the assumption that success is possible only when failures do not occur at all.

So the goal is not to compromise performance. A smart approach requires preparing to create flow by addressing the underlying problems, and then moving forward in a meaningful and purposeful manner, starting with planning and developing a problem-solving discipline. As the process improves and is reproducible, further leveling is carried out, within which the control parameters are made even more stringent, which allows the next layer of problems to be identified during the next cycle of continuous improvement.

WHY FLOW?

Most often, implementation failures stem from the mistaken belief that success is rooted in the application of lean tools (for example, creating a cell). We often arrange visits for our clients to lean factories, sometimes to Toyota plants, and it can be very interesting to hear what they take away from such excursions. They are usually impressed by cleanliness, order, discipline, thoroughness and people focused on their work. But when they see something that they can immediately apply in their own enterprise, their eyes literally light up.

One day during a tour of a lean facility, someone noticed that next to each cell there was a small cabinet with supplies and the cell leader wrote out the materials as needed. To replenish the stock of, say, plastic gloves, a kanban system was used. Our “industrial tourist” was burning with impatience to return to his factory and create a similar ordering system Supplies. Unfortunately, he noticed only one tool and lost sight of the interconnectedness and interdependence of the entire set of elements. For successful creation The lean process requires a good understanding of how a particular tool works to achieve a goal. It is unlikely that an experienced mechanic, when repairing a car, will first take the first wrench he comes across and then start looking for a suitable nut for it. First of all, he will determine the essence of the problem and the measures that will eliminate it, and only then will he select the tools necessary for the job.

And yet, we often see organizations reaching for tools before understanding what is happening. “We're going to implement visual controls,” managers say, as if it were a puzzle piece that needs to be slotted into place. The key to long-term success is a shared effort that includes reflection. basic principles or concepts, effective strategy, which presupposes the mandatory implementation of this concept, the methodology for applying this concept, lean manufacturing tools for implementing the chosen method and an effective approach to measuring the overall result.

We believe it is useful to think about the relationship between unit flow and cost reduction in the context of a broader model, as shown in Figure 1. 5-1. Instead of jumping headlong into creating flow and a pull system, stop and think about what goal you want to achieve. This model emphasizes the connection between the core principle of lean manufacturing - identifying and eliminating costs - and the method of achieving this goal - reducing batch size, which moves closer to creating a continuous flow. Creating continuous flow is often considered the primary goal of building a lean process, but in fact, creating continuous flow is aimed at eliminating waste in all operations. The primary task is to eliminate losses.

When material and information flow in a continuous flow, the amount of waste in the process is reduced. This is true by definition. Significant volume losses will not allow the creation of a flow of material or information. However, what is happening also has a deeper meaning. Maintaining a continuous flow between processes ties them together and one process becomes dependent on the other. This interdependence and the limited volume of buffer stocks make any flow disruption more serious.

Anyone who has tried to create a one-piece flow (and it really is not an easy task!) understands that exacerbating problems can be a big advantage... or a huge detriment. In the absence of effective system support, exposing problems is tantamount to a death sentence. This is why lean manufacturing tools are so important: they can create a structure that will help you achieve success and avoid failure. Lean manufacturing tools promote the creation of both support systems and control methods that allow you to adequately respond to identified problems.

LESS IS MORE: REDUCING LOSSES BY CONTROLING OVERPRODUCTION

True one-piece flow means that each operation produces only what the next one currently needs. If the next operation is stopped for some reason, all operations preceding it are stopped. It would seem that what could be more unpleasant than stopping. However, the alternative to stopping work is overproduction, where we produce more or faster than the next operation needs. Toyota considers overproduction to be the most dangerous of the seven types of waste, since it gives rise to the other six (excess inventory, unnecessary movements, unnecessary processing, hidden defects, etc.). This allows you to understand how less can become more (less means fewer parts produced in individual process steps, more means increasing the proportion of value-adding work in the overall process). Below is an example typical situation overproduction, which negatively affects the satisfaction of consumer requirements.

Case Study: Overproduction Control Improves Operational Availability

Standing in a circle and observing the production line revealed that overproduction is extremely common. Product stocks accumulated along the line - products lay in stacks. All workers were constantly busy, but we noticed that operators spent a significant amount of time storing excess product. When there was no work, most operators tinkered with inventory (the result of overproduction). Comparing cycle time with takt time showed - and this was not surprising - that the duration of all operations was less than takt time, which meant that operators had extra time. Since they were not performing other value-adding tasks, they spent that time overproducing and handling inventory.

In addition, observation showed that as a result of overproduction in the next operation (consumer process), additional time is spent moving and unpacking products arriving in large quantities, and this creates additional inconvenience. The cycle time of this operation fit within the takt time, however, due to extra work The total time required to move and unpack products exceeded the takt time, and as a result, the operation could not meet customer requirements within the planned working hours. In this case, the excess losses were created by the supplying process, and Negative consequences detected by the consumer process.

We asked operators who were performing previous operations to stop and stand without causes, rather than continuing to work despite the fact that the next process is swamped with excess material. Of course, the operators felt very uncomfortable, because their superiors instilled in them that it was unacceptable to stand and do nothing. The importance of this approach is well understood at Toyota, as it allows everyone to see and understand the scale of the opportunity. When the picture is not foggy hectic activity (overproduction), everyone sees how much time is wasted.

When did the operators start working? less(manufacture fewer parts), the loss of time for consumer processes was reduced and they could spend it on promotion productivity. Controlling overproduction has significantly increased the overall yield of the process as a whole.

Of course, we were not happy with the operators standing around doing nothing - waiting is also a type of loss. Next, it was necessary to decide how to eliminate additional losses in performing these operations and, by combining operations, to achieve “full utilization”. Analysis of standardized work helped solve this problem (an example of such analysis is described in Chapter 4).

Case Study: Creating Flow in Aircraft Repair at Naval Air Station Jacksonville

Repair work have even greater variability than production. It is possible to understand what the problem is and how long it will take to fix it only after a thorough examination. Therefore, repair is often viewed as a craft job that requires the collective participation of a whole team of specialists. It feels like a throwback to the days of yore, when a team of craftsmen gathered around a booth to assemble a Model T Ford.

The US Department of Defense carries out a huge amount of work to repair and modernize ships, submarines, tanks, weapons systems and aircraft. These are all very large objects. Aircraft repairs almost always need to be done urgently. If a fighter is in a repair hangar, that means there is one less aircraft ready for battle.

The largest facility in Jacksonville, Florida, is an air base that repairs U.S. Navy aircraft. Aircraft periodically come in for major repairs, and some of them also have serious defects that require special treatment. Since the aircraft needs to be adjusted and returned to service as quickly as possible, as soon as it arrives at the base, it is rolled into a hangar and qualified personnel get to work, dismantling the aircraft into parts. The skin is removed from the aircraft, individual components are repaired or replaced, one part after another is checked, and finally it is reassembled, after which the aircraft is again ready to take off. There is another incentive to complete the work immediately - payment. The base bills hourly for aircraft repairs.

Although aircraft repairs at the air base have been carried out for decades, the need to reduce the time an aircraft spends on the ground remains very pressing. It happens that aircraft are taken out of production, which leads to a reduction in the fleet. If aircraft sit in a repair hangar for too long, the time to complete planned combat missions is reduced. Command aviation systems The Navy has launched the "Air Speed" program to speed up the process of repairing aircraft in the Navy's aviation enterprises.

Two aircraft were received in Jacksonville for repairs - RZ and F18 fighters. Repair work was carried out in different hangars. Hired consultants worked at the base as lean manufacturing experts. They supervised the work of teams mastering lean manufacturing and helped them acquire the relevant knowledge and skills. Independently of each other, experts analyzed the current situation for RZ and F18 and came to the same conclusions:

Each aircraft was considered as unique project, and the technicians who repaired it did not use any standardized process.

The work area around the aircraft was cluttered with tools and parts that were lying around haphazardly.

Maintenance workers spent an inordinate amount of time walking around searching for the right tools, parts, and supplies.

After disassembling the aircraft, the parts were placed in boxes and sent to storage facilities (for this, for example, automated system storage and transportation), and when the parts are returned from the warehouse so that the aircraft can be reassembled, a lot of time is spent disassembling the boxes and finding the necessary parts. Parts often went missing because they were used to repair another aircraft. Repair of several aircraft is carried out simultaneously, and when for some reason (for example, a shortage of basic parts) work on one of them was suspended, the mechanics were transferred to work on another aircraft.

There was a belief that the arrival of aircraft for repairs was unpredictable and it was impossible to draw up a plan that would ensure a stable, leveled volume of work.

Value stream mapping revealed great amount losses in existing processes. Maps of the future state were developed, where solutions of a uniform nature were proposed for all aircraft:

The process of disassembly, fault analysis, repair and assembly should be divided into clear steps.

It is necessary to create a production line for each repair area, each of which must perform a certain type of work.

It is necessary to bring the line operation into line with the takt time. Analysis of actual data showed that the supply of aircraft is much more stable than is commonly believed.

A standardized work procedure should be developed for each site. I

To stabilize the process and reduce the amount of non-value-added walking around searching for tools and parts, the 5S method should be applied.

It is necessary to create a “stationary” so that if work on one of the aircraft is suspended (for example, due to waiting for parts that take a long time to manufacture), the aircraft can be placed in it and the overall flow will not be stopped. Management must know the process thoroughly and stop the practice of accepting aircraft at any time. It is necessary to keep the volume of work in progress under control, not allowing the number of aircraft to exceed the number of repair areas on the production lines (this will be discussed below).

The work area was divided into work stations. This presented a technically challenging task of moving the aircraft from one place to another. At some point, the plane was completely disassembled: the wings and landing gear were removed. The F18 fighter was a new aircraft for the base, and it was possible to purchase a rig for it, which was a huge contraption on wheels that allowed the disassembled aircraft to be moved from one repair area to another. However, it was impossible to do this with the RZ fighter, and in this case it was decided to create a “virtual production line.” Maintenance crews approached the aircraft at set intervals to perform a specific type of work. This meant that they had to take with them the tools and materials needed for the operation in question.

To debug individual components of the system, several practical kaizen workshops were held. Among them were seminars on 5S, during which the work area at the base was redesigned, everything had its place and standard places were marked. Practical material flow workshops helped develop a more streamlined approach to aircraft dismantling. Now the aircraft parts were placed in special boxes, and when they were returned from storage, they were all as they should be. Hazardous materials were placed on carts in containers. All containers, parts and materials were replenished using pull systems By to the extent that cash reserves are used. Started off slow and difficult process detailed analysis of each operation to develop standardized work procedures and bring the pace of work of each section in accordance with takt time.

The RZ fighter is a fairly old model that will soon be withdrawn from service. The Navy decided to reduce the fleet of these aircraft by 50 units, from 200 to 150, with the condition that about 120 of these aircraft were constantly in combat readiness. To ensure the combat readiness of such a number of aircraft, it is necessary to reduce the time Maintenance. Since these aircraft have experienced fuel system problems and fatigue due to aging, the need for additional mechanical strength testing makes the repair requirements more stringent and therefore further complicates the work, which must be completed under very tight deadlines. It could be said that from a Navy perspective the situation was a crisis, but from a Lean perspective it was an ideal opportunity to demonstrate the value of eliminating waste.

Before additional requirements for testing and work were imposed, the repair of such a fighter took 247 calendar days. To constantly maintain 120 aircraft in combat readiness, it was necessary to reduce the cycle time to 173 days, i.e. by 30%.

The official development of lean manufacturing under the guidance of an experienced consultant 5 began in April 2004. Less than a year later, by February 2005, after value stream mapping and numerous hands-on kaizen workshops, the results shown in the table became visible.

It is one thing to establish a process, another to manage it. This skill required a completely different approach to management than the one to which current managers were accustomed. It was necessary not only to deal with a variety of tools - 5S, standardized work, problem solving, etc., but also to stop attempts to accept an excessive number of aircraft. The last task was one of the most difficult. The basis of the flow concept is a fixed amount of work in progress. The line has a certain amount of work areas and a “stationary”; there are no other places for aircraft in the hangar. When the repair of one aircraft is completed and it leaves the hangar, the next one can be accepted.

This contradicted all the guidelines of the managers and the accepted system of indicators. First, management was convinced that if the aircraft remained outside the hangar, it would take longer to repair it. The adoption of lean manufacturing has proven just the opposite - lead times are significantly reduced when working on a fixed number of aircraft. Accept

another plane is possible only after space at the beginning is freed production line, and until then it is better to leave the plane outside the hangar. Secondly, it used to happen that workers were left idle because all the work on repairing the aircraft in the hangar had been completed. Managers were wary of this situation because they were judged by the hours the production workers worked, and it was for these reasons that support labor was provided in the hangars. At times, when a new aircraft arrived for repairs, one of the higher management ordered it to be accepted for repairs. The lean consultants had to use all their influence to get the plane out of the hangar. It was a real culture clash.

The Navy was amazed at the results. The Jacksonville base soon became a favorite excursion destination. staffing The Navy, Air Force, Navy Aircraft Depot, and other organizations that wanted to see true lean manufacturing in action. The airbase has become a role model. The most surprising thing, perhaps, was that the aircraft were repaired on a line resembling an assembly line. Creating a production line with a given takt time allowed for continuous improvement, eliminating waste and ensuring balanced operation of the line as a whole. Chaos and disorganization began to replace control and stability.

STRATEGIES FOR CREATING A CONNECTED PROCESS FLOW

Table 5-1 presents strategies for creating a cohesive process flow, as well as commonly used basic and supporting tools.

lean manufacturing. Depending on the circumstances, you can use both those tools that were already used at the stabilization stage and additional ones. As for the above-mentioned goals and strategies, they are all required.

SINGLE ITEM FLOW

The quest to create one-piece flow—the ideal of flow—has become something of a fad, with many companies failing to achieve this level. Creating a one-piece flow is an extremely complex task that requires a well-established process and special conditions. Often it is simply impossible to create such a flow; in other cases, before you can reach this level, you need to go through many turns of the spiral of continuous improvement.

As an analogy, imagine a line of people passing buckets of water at a fire. At one time, only one bucket is passed from hand to hand. This creates a flow of single items when an item is transferred from one participant in the chain to the hands of another. This requires perfect coordination among all participants in the chain. Having passed a bucket to his friend further down the chain, the chain participant immediately accepts the next bucket from his neighbor on the other side. If the rhythm of the movements of two participants in the chain is not coordinated, one of them will have to wait for the other, and this is one of the types of losses. Achieving flawless coordination is extremely difficult and is only possible with clearly agreed-upon cycle times. If anyone in the line hesitates a little or makes a mistake, it will unsettle everyone else and the house will burn down.

In most one-piece flow manufacturing plants, one piece is placed between stations, and thus the slight variation in an individual worker's cycle time does not create a wait. However, even at this level, the balance of cycle times of individual operations must be extremely high. The presence of additional products between operations allows you to work with a higher variation in cycle time in different operations, but this approach leads to an increase in overproduction, which represents losses. This is a real puzzle. Reducing buffer stocks between operations reduces overproduction, but increases losses due to unbalanced work cycles.

When moving towards creating lean processes, you should stick to the golden mean. Along with resolving a certain number of pressing problems that cannot be ignored, care must be taken to ensure that insurance is in place until the reproducibility of the process allows the process steps to be more closely aligned. The spiral model of continuous improvement discussed in this section, ensures the reproduction of this cycle. Incremental equalization requires reducing the amount of buffer stock throughout the flow, which leads to the identification of increasingly smaller problems. This again causes instability, and the spiral makes a new turn, leading to new level efficient work in more severe conditions.

CLUE

When is a problem not a problem?

At Toyota, managers are required not only to stop work and fix problems, but also to constantly and vigilantly identify potential problems before how they arose. In a well-functioning lean manufacturing environment with continuous, connected flow, there are certain signs that the system may be failing that serve as “warning indicators” for everyone to see. The ability to identify problems before they occur allows managers to take proactive corrective action and thus prevent failure. Note: Toyota does not believe that failure is always a bad thing.

In essence, the absence of failures in the system is considered an indicator of excess losses. The inability to predict when and where failure will occur is an indicator of an ill-designed system.

IMPORTANT CRITERIA FOR THE PRESENCE OF FLOW

As we said in the previous chapter, a number of conditions are necessary to create an uninterrupted flow. Typically, these criteria are met during the stabilization phase, but we will repeat them again.

The primary task of stabilization is to ensure stable reproducibility, at least during the day. The process must meet customer requirements on a daily basis.

Sustainable reproducibility requires stability in resources—people, materials, and equipment—and their availability. Failures in resource availability are the main obstacle to thread creation. It is necessary to use methods that ensure the availability of resources (this is not just about increasing the volume of resources, which increases costs).

An indispensable condition is the reliability of the process and equipment. In the early stages, it's about larger issues such as downtime and changeovers, but as the process matures, attention should also be paid to smaller ones, such as ease of use.

The work cycle time must correspond to (be equal to) the takt time. If operations have different cycle times, waiting and overproduction occur.

TRAP

Trying to prematurely create one-piece flow is risky.

We've seen company representatives come back from lean classes excited about the flow of one-offs and immediately get to work creating cells. However, they soon discovered that the cell was idle most of the time, and came to the conclusion that lean manufacturing did not work in the real world. The phenomenon that gave rise to their problems is called “piece-through output.” Let's take a situation where five machines are lined up in a flow of single products and each of the machines is faulty 10% of the time, in other words, operational 90% of the time. The time that the cell remains in working condition will be:

0.9 5 =0.9 X 0.9 X 0.9 X 0.9 X 0.9=59%!

Solution: Store a few units of work-in-process between operations, carefully considering where exactly such buffer stock should be provided. This will increase the productive operation time of the cell by up to 90%.

Specific situation: danger of creating one-piece flow for processes with short cycle times

The transition from traditional batch and queue processing methods to material flow has become a fad. With most fashion hobbies there are extremes that cause negative consequences. In many cases, being carried away by the flow of single items leads to a decrease in performance indicators. The flow of single items may not be the most effective method with short cycle times (30 seconds or less).

The objective of one of the practical kaizen workshops was to create a flow of single items during an assembly operation. The product was a fitting, the assembly of which took 13 seconds. The takt time based on customer demand was 5 seconds. The work was distributed between three operators and created

cell (another fad) to transfer product from operator to operator, which is necessary to create flow.

Several months later, the site was struggling to meet customer demand, and operators were again stockpiling product runs between operations. As the cycle ratio graph in Fig. 1 shows. 5-2, the cycle times of the operators were not balanced properly.

This imbalance is the main reason why operators deviate from the “no batch” rule. If operators deviate from the original plan, this clearly indicates a failure of the plan. Unfortunately, usually in such cases, management tries to force subordinates to follow the rules and maintain flow, rather than stopping and reflecting on the shortcomings of the process. Learn to perceive deviations made by the operator as a positive phenomenon! Stop, observe and identify the real cause of the problem. Eliminating it will benefit the process.

Even if the cycle times are properly balanced and a smooth flow is created, there is another less visible problem. Trying to create a flow of one-piece items with very short cycle times generates a high waste ratio, which is calculated as the ratio of waste to value-added work. Here's why this happens: in any workflow, there is a certain amount of unavoidable waste, such as taking a part and putting it in the next operation. These losses can be minimized, but in the best scenario, one movement will take from half a second to a second (pick up and put down). Suppose the conditions are optimal, and this operation takes

second during the work cycle - half a second to pick up a part, half a second to put it down. We get a second of extra movements during the cycle. If the cycle time is five seconds, one second spent moving material is 20% of the total cycle time! If the operation is carried out in 3 seconds, this figure will exceed 30%. This is a huge percentage of losses. However, such waste is often overlooked because it is assumed that because material flows and operators are constantly moving, we have lean manufacturing. As you can see, this is not at all true.

This operation can be improved by not breaking the job into many different operations in an attempt to create flow, but by having two operators take the part and process it from start to finish. This will reduce the time by two seconds, resulting in the job being completed in 11 seconds (Figure 5-3). The net time spent processing one product is 5.5 seconds (two people working simultaneously produce two products every 11 seconds, 11 divided by 2 = 5.5 seconds per unit), which exceeds the takt time by 0.5 seconds. The next step is to reduce other waste and simplify the operation so that it can be completed in 10 seconds or less and a unit processed in 5 seconds or less.

In this example, creating a thread resulted in a 33% performance hit (three operations instead of two). Moreover, on the scale of the entire value stream, this operation was a small fraction of the total material flow. There were far greater opportunities to create flow and reduce overall cycle time by linking activities in other areas using the pull methods described below.

PULLING

The terms "pull" or "pull system" are often confused with "flow". It should be understood that pull, like flow, is a concept. These two concepts are related, but do not mean the same thing. Flow is the state of a material as it moves from one operation to another. Pull determines when material movement occurs and who (the consumer) dictates the need for this movement.

Many people do not understand the difference between push and pull methods. Some people mistakenly believe that they are engaged by pulling as the material continues to flow. However, flow can exist without pulling. Pulling differs from pushing in three main ways:

1. Certainty. The presence of a clear agreement between the supplier and the consumer, which sets the limit values ​​for the volume of production, assortment and sequence of production.

2. Consolidation. Objects shared between two named parties must be assigned to them. This applies to resources, location, storage, containers, etc., as well as the overall timestamp (takt time).

3. Control. Simple control methods using visual warnings and physical restrictions as agreed.

In a push system, there is no agreement between supplier and customer regarding the quantity of work to be delivered and the timing of delivery. The supplier works at his own pace, guided by his own work schedule. The material is then delivered to the consumer, whether the consumer requested it or not. The location of the material is not defined, and it is placed wherever there is free space. Since there is no certainty of mutual obligations and location, it is impossible to develop a clear method of control, since it is not clear what and how to control.

Of course, the situation is partly controlled by expediting dispatch, changing the schedule and rearranging people, but this only creates additional losses and variation. Of course, one could argue that the terms of the parties' contract are determined by the schedule. All processes operate according to a single schedule. The schedule may indeed be uniform, but this still does not ensure coordinated actions.

A pulling system is a collection of several elements that support the pulling process. The Kanban signal is one of the tools used as part of a pull system. Kanban is just a method of communication, it can be a card, an empty box, a cart or other signal with which the consumer says: “I am ready to take the next portion.” In addition, there are other elements, including visual inspection and standardized work. If the three named elements of the pull system function properly, there is a “linking” between the supplier processes and the customer processes. The three listed elements determine the parameters of “linking” and how close and stable this connection is.

The specific situation described below illustrates by example the three requirements that a pull system must meet. These are most easily illustrated and conceptualized in a single-piece flow, but the same principles apply to any variation and in any situation, whether producing a wide variety of products in small batches or working in batches where the volume of output between processes is much larger. We took the most easy-to-understand example, but the principles mentioned are applicable in any conditions.

Case Study: Creating a One Piece Flow

Operation A supplies parts to Operation B, which supplies parts to Operation C.

Is there a clear contract with specific terms and conditions?

Yes. We said that this is a flow of single products, and this very definition implies specified quantity. (As we will see later, implied definitions are not enough.)

What are the terms of the agreement?

Supply of products one at a time.

At what point does the submission take place?

When is the previous product accepted at the next operation (remember the line of people with buckets at the fire)?

By observing what is happening, we can determine whether the contract is being fulfilled. In Fig. 5-4 we see that operation B does not fulfill the contract and exceeds the specified limit (one product).

How to determine whether a contract has been violated?

The term "unit item flow" implies that there should be no more than one item between operations. THIS IS NOT ENOUGH! The terms of the agreement must be extremely clear and presented in a visual way accessible to everyone form.

What happens if they are not clear and presented clearly?

The contract will not be respected, this will cause deviations (create variation) from the agreed standard (we see that by creating a pull system, we begin to create a structure that supports the next stage - standardization).

How to provide visibility, which will allow Is it easy to control the situation?

Define space for a single product and secure him behind him. Outline this area with tape or paint so that it is clear that only one product is allowed here, and provide the designation with an explanatory inscription so that it is as clear as possible (if the outline of a square is applied to the table, you should add an inscription or symbol explaining what this means). square), as shown in Fig. 5-5.

In addition to visual markings, you can limit the physical space so that only one product fits in a given space. This technique is especially effective when the parts are oriented vertically and can be inserted into a special recess, thereby controlling the quantity.

One of the main benefits of flow and clear agreement is that the consequences of problems are now made explicit. If in the example above, the means visual control indicate a constant deviation from the terms of the contract, which means another problem has arisen.

Deviation clearly indicates that there is a hidden problem that needs to be solved. In such a situation, managers often complain: “They know perfectly well what to do, but we can’t get them to work as expected.” Many managers make the mistake of blaming the operator for not following the rules when in fact the operator's actions are compensating for a problem that needs solving. Stop and stand in a circle to determine what deficiency the operator is compensating for.

There are usually two reasons for this situation. First, you need to make sure that the terms of the contract are presented visually in a form that everyone can understand; secondly, check whether there are additional problems that the operator is forced to work around.

The main reasons for deviations in the operator’s work are:

1. An imbalance in the cycle time of individual operations, which may be caused by normal variations in the volume of work, the skill of the operator, or the cycle time of the machine. Usually the one who deviates from the rules is the one who has extra time.

2. Periodic downtime due to lack of parts (or fear that parts will run out). Operators leave the work area to take over execution additional functions- for example, bring parts or check their quality. Suspension of work due to equipment failures or correction of defects.

3. Intermittent suspensions due to difficulties in operating equipment or fixtures, or when performing overly complex operations.

4. Various reasons, for example, the desire to create a reserve in order to gain time for changeover, sometimes the operator leaves the line for some reason, goes for lunch or a break sliding schedule, as well as other reasons of this kind.

In some situations, it makes sense to adjust the amount of work in progress depending on the operation. Single piece flow requires flawless balancing the duration of operations, which is an extremely difficult task. Imagine an operation, such as deburring an injection molded part, where worker time variation is common.

Cycle times will vary slightly each time because most of the work we do is done manually and no one can cycle through it multiple times in the same amount of time (even Olympic athletes can't run the same distance twice). with the same result). This slight variation can cause intermittent flow glitches. Operators do not like to sit idle, and to compensate for the problem, they begin to increase buffer stocks. Increasing buffer stocks is a logical choice to compensate insignificant time variations; however, the volume of build-up should be limited to the standard. In this case, the agreed buffer sizes, compensating for minor time variations, should be no more than two or three units of production.

CLUE

The benefits of an outside perspective

Often communication difficulties are caused by the fact that it is difficult for us

- “j/ realize why others do not understand seemingly obvious things. The point of a standard terms agreement is to ensure that those terms are understood by everyone on the same page. To check how successful you are, find a person unfamiliar with the work area, show him the standard and ask him to explain the essence of the contract. You'll be surprised at how difficult it is to communicate the terms of a contract using visual media!

WORKING WITH COMPLEX FLOW

Looking at a more complex example, we will see that the same concepts are used here as a basis. In our case, three different product models are being produced - 1, 2 and 3 - and we need to provide flexibility that will allow us to produce one of these models at any time. Organization diagram

Suppose Operation C requires the production of Model 2. The operator takes one product from a given place between Operation B and Operation C. According to the terms of the contract, this serves as a signal for Operation B: the empty space is a signal, and when the consumer pulls out the product, this should be signaled the next place is to make a part for model 2. Now the situation corresponds to Fig. 5-7.

Operation B then picks up part 2, which is between operations A and B, which prompts operation A to start making part for model 2. When the job is completed, operation B replenishes the stock between operation B and operation C. The picture now matches Fig. 5-8.

Of course, this is a simplified model, but it does all three necessary conditions and their compliance is supported by visual means. This basic model is applicable to high-volume or low-volume production, or to handling inventory. Its main advantage is flexibility, which allows you to produce any model at any time and quickly switch from one model to another.

Question 51 What is the process approach in management? Answer Process approach is to consider management as a process, since achieving goals with the help (through) other people is not a one-time discrete action, but a series of continuous

Chapter 1 Process approach: concept of implementation in an organization 1.1. Company maturity in the field of process management In order to successfully implement a process approach to management, company managers must clearly understand what it involves process management how will they be

1.4.2. Process approach at the level of the organization as a whole. In Fig. 1.4.1 shows three levels. The changes that arise when implementing the process approach at the level of the organization as a whole are presented in Table. 1.4.1.Table 1.4.1. Elements of a process management system at the level

60. SITUATIONAL AND PROCESS APPROACHES TO MANAGEMENT The capabilities of the situational approach: 1) represents the possibility of direct application of scientific methods to specific situations and conditions; 2) the situational approach preserves the concept of the management process; 3) he

How to ensure a large flow of resumes? First of all, you need to increase the number of calls to your company. There is a special resource for this - the website www.hrhome.ru with a system for instantly posting vacancies. Post vacancy announcements through this and similar ones

The synchronized production system is an advanced method of organizing production that allows your company to minimize losses, significantly increase profits and achieve outstanding results. The book describes in great detail all the stages of building synchronized production: from the introduction of visual management in the enterprise to the construction of a pull production system and continuous improvement of the entire production activities. The peculiarity of this publication is its exclusively practical orientation. Each stage of the synchronized production system is described in detail and supported by advice on its implementation, numerous illustrations and practical examples.

Hitoshi Takeda. Synchronized production. – M.: Institute of Complex Strategic Studies, 2008. – 288 p.

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Introduction. To achieve a state of synchronized production, as a rule, you need to rise to four levels of production culture (Fig. 1). The book proposes to break down the implementation of synchronized production into 13 stages, each of which is described in a separate chapter.

Rice. 1. Perfect production condition; To enlarge the image, right-click on it and select Open image in new tab

Stage 1. 6S Concept

Most of the changes needed to reform production can be carried out using the 6S concept. To put the 6S concept into practice, the entire staff must be involved: everyone must be interested in the changes, otherwise there will be no benefit from 6S.

WHAT IS 6S?

• SEIRI – sorting; freeing workers from unnecessary items and organizing a storage system.
• SEITON - rational arrangement; arrangement of the necessary items in an order that makes them easier to find and use (Fig. 2).
• SEISO - cleaning; maintaining cleanliness in the workplace.
• SEIKETSU – standardization.
• SHITSUKE - improvement.
• SHUKAN is a habit.

It is necessary to radically change the existing ideas about both the workspace and the principles of production organization. Many behavior patterns are so deeply ingrained that people are simply unaware of them. The goal of implementing 6S is to recognize these habits and radically change them so that there is no return to previous ways of working. Reforming production is impossible as long as the staff behaves as before.

Stage 2. Leveling and smoothing production

The period during which a product is produced is called takt time. A method that allows products to be produced in accordance with takt time is called smoothed production. Each machine must process products in accordance with the takt time, otherwise the machines will be idle every now and then or work under overload. Resolutely eliminate all stocks: they cause only harm. When inventory levels drop, different types of problems come to the surface. It can be formulated in another way: without eliminating losses, you cannot get rid of stocks.

Smooth production allows you to reduce inventories at all stages of production. Synchronized production should be built in the direction opposite to the movement of products, that is, first introduce it at the last production stage, and then move to the first stage. It should be remembered that the pursued goal is to achieve the efficiency of the axes of the production system, and not its individual elements (for more information about the dangers of local optimization, see, for example,).

Production leveling is the distribution of production volumes, allowing each shift to produce the same number of products. Production smoothing is the equalization of the volumes and types of products produced daily. The ultimate goal of smoothing production is to produce products that meet consumer requirements with a minimum of production costs.

Leveling => Smoothing => Increasing the number of cycles (Fig. 3).

Rice. 3. Leveling, smoothing, increasing the number of cycles; * – there may be a typo in the picture, you should read 20

Stage 3. Unit flow

One-piece flow allows you to coordinate activities at different stages of production. However, many enterprises still produce products in large quantities, which leads to a pile of inventory that accumulates at each work station. When there are many operators on the line, the ability to work as a team becomes especially valuable. One-piece flow helps optimize team operations.

For the efficient functioning of the flow of single products, it is necessary to establish a standard buffer stock - a minimum stock of parts and products on the line, ensuring continuity of the flow. Buffer stock is stored near workstations. When forming effective flow single products, you need to pay attention to three main points: equipment, personnel and production (Fig. 4).

Stage 4. Flow production

In a manufacturing context, "flow" refers to the continuous movement of products through all stages - from the supply of material to the finished product. Raw materials, standards for performing operations, kaizen events, and exchange of information between processes are the elements from which the formation of an effectively functioning flow begins. The end result that this method of production leads to is the production of only necessary products and the standardization of all operations and processes in the enterprise.

The first step is to create a backlog of parts at the end of each production line. Workers must perform operations in a strict sequence, then the flow will be smooth. To do this, it is necessary to train operators to operate several machines, that is, to expand their qualifications. Then, using kaizen methods, you should reduce the inventory level of the necessary parts (this should be done gradually, step by step). In particular, the U-shaped arrangement of the equipment will allow maintaining the continuity of the flow. Machines should be positioned as far as possible closer friend to a friend in the same sequence in which the operations are performed.

It is advisable to place equipment in workshops counterclockwise. Why is this so? The product flow moves from right to left, and right-handed workers pick up workpieces with their right hand and change the position of switches with their left hand.

For efficient functioning continuous production workers must have several skills. This will allow you to vary their loading. Depending on their skill level, workers are divided into three groups: groups A, B and C (Fig. 5).

Visual and audible signals are visual controls. They are used to alert about deviations from the normal course of work and interruptions in flow continuity. If problems arise with quality, mechanical defects or malfunctions, the worker must press the button and call the foreman or a member of the repair department. If a problem arises, do not rush to stop the line, but call the foreman or foreman. He will stop at the right moment (when other workers have completed the cycle). In those cases: when the lines are equipped with a stroke limiter, if a malfunction occurs, the stop will occur automatically (Fig. 6).

Step 5: Reduce Batch Sizes

Reducing batch sizes, which is inextricably linked to reducing changeover times, is carried out in order to produce only the necessary products in the required quantity and at the right time, and also to better respond to fluctuations in consumer demand and changes in market conditions. Inventories should be minimized and production costs- decrease. Mastery of quick changeover operations is an important condition that contributes to the formation of a continuous flow of single products and increased profits.

Among various types The most dangerous loss is overproduction. Overproduction leads to excessive workload of workers on processes, hides problems, increases the buffer stock, which, in turn, generates new losses. To achieve an efficient production system, you need to figure out how to reduce the buffer stock and organize a continuous flow of single items. Releasing products in large quantities is a direct path to overproduction. In order to optimize changeover operations, it is necessary to abandon existing stereotypes and form new order performing operations (Fig. 7).

Signal kanban is used on lines where products are produced in batches. Triangular kanbans signal the start of production, while other types of kanban signal the removal of materials. Kanbans are a means of coordination and information transfer, with their help the volume of products is regulated and batch sizes are reduced. Proper use of kanbans and containers increases production efficiency.

Stage 6. Storage areas for parts and products

Although this chapter focuses on the production line, the principles that optimize the flow of information can be successfully applied in offices, service organizations, and other sectors of the economy. Visual management tools allow any worker to assess the production situation without searching for any additional information. It is especially important for managers to be able to monitor the pace of production directly on the shop floor, since in this case they can instantly respond to any deviations that arise.

The basic principle that should be followed when developing designations for the location of objects is that every detail should have its own place. For example, a part is identified by a number, a location by a letter designation.

After assembly, finished products are immediately moved to a designated storage location, so finished product storage should also be considered as part of the production process and, accordingly, all rules regarding the organization of storage and movement should apply to them. The same applies to the principle of “first in, first out”: this principle should become universal.

Containers should be used to store and move products in the enterprise. It usually doesn't occur to us to consider empty containers as indicators. When production rules have been developed for using containers as indicators of material levels, identifying material shortages by counting empty containers is not difficult.

As part of the synchronized production system, all storage facilities are self-regulating. If the operation of the storage facilities is not automatically adjusted according to the needs of the downstream process, this means that the storage facilities are not fulfilling their role, but are simply a place in which excess production accumulates.

Step 7: Production according to takt time

Takt time is the time interval for product release, set by the subsequent process (consumer). Work in progress should be kept to a minimum, but care must be taken to ensure that downstream processes receive the required parts in the required quantity at the right time. Takt time is calculated by dividing the available working time by the number of products that need to be produced per shift.

When releasing products, you should avoid slowing down or speeding up the pace. There is nothing worse than releasing products ahead of schedule (Figure 8).

Do you think your production line is in the worst possible condition? Eliminating waste starts with recognizing the shortcomings. In an effort to identify losses, do not immediately try to figure out how to eliminate them; you'll do that later. First, it is very important to identify losses, down to the smallest. After this, you can move on to sequentially, step by step, eliminating them. Thus, the ability to see losses (muda) around is developed (Fig. 9). When reducing the number of workers on a line, the most skilled workers should be removed first. Before being transferred to other areas, these workers must be assigned to carry out kaizen activities on the line for a month. The true measure of productivity is easy to track when production volumes are reduced. When production volumes increase, in no case should the number of workers employed on the lines be increased.

Stage 8. Control of production volumes

Improvements should help reduce costs. In order to visually present the results of these actions, one of the visual management tools is used - a schedule for recording and distributing production volumes. Its main purpose is to help create a flexible, continuous flow that functions without disruption.

Controlling production volumes helps to accomplish three important tasks:

• foremen, workers and senior managers receive specific numbers and their visual display, which allows them to substantively discuss the situation and ways to improve it;
• control of production volumes helps to maintain delivery deadlines;
• production volume control allows you to track production costs.

Production status monitoring, carried out every hour, allows you to quickly respond to deviations. It also helps to develop a conscientious attitude among workers to carry out production tasks, because, having information about the current situation, they can regulate the pace of work themselves, if necessary. In this way, it can be ensured that by the end of the shift, the needs of the downstream process will be fully satisfied. This method also allows you to track production time for each product and monitor how much production costs have been reduced during the shift.

Two types of schedules are used as tools to take into account and control production volumes and production times of individual products:

• Production volume control schedule. Every hour throughout the week, data on current production volumes and product manufacturing times are entered into the schedule. the data is then compared with planned indicators and analyzed. Regular use of this chart allows you to identify bottlenecks in production.
• Graphical display of fluctuations in production volumes and production times. Based on the data from the previous graph, a diagram is drawn that compares actual and planned data on the time and volume of production during the month. This allows you to see the dynamics and understand how to proceed.

If nothing changes, production costs will certainly increase. The most significant losses are caused by the following factors:

• downtime on the line (costs of paying idle workers, costs of storing work in progress, other costs);
• personnel errors (repeated processing, loss of consumer confidence);
• mechanical defects (decrease in production volume, losses due to quality defects, repair costs);
• errors in planning (additional shifts, overtime pay);
• incompleteness of kaizen actions (losses due to unused potential, low productivity).

To develop leadership qualities, you must adhere to strict self-discipline and be prepared to self-learn. The responsible foreman ensures that workers complete assigned tasks. Labor safety on the site, the quality of products, quantity of products, production time of products and the level of production costs largely depend on the behavior and views of the leader.

The responsible foreman is one of the most important links in the chain of formation of a synchronized production system. He must convince workers that improvement is impossible without effort. The workers are not used to standing idle. If you don't look after them, they will start doing work that should not be done under any circumstances. The foreman must convince workers to refrain from working during the waiting period.

Three tasks that the foreman must ensure: ensure high quality products, meet delivery deadlines, and reduce production costs.

Stage 9. Standardized work

Standardized work is the central element of a production system. Moreover, it would not be an exaggeration to say that without the use of standardized work, synchronized production does not exist. The most important aspect of standardization is to create a system that will support ongoing compliance with standards. Standards should be strictly followed, even if they are far from perfect, since kaizen in an enterprise is only possible if there are standards. To ensure that workers do not neglect standards, it is necessary to involve them in the process of creating standards.

Five tasks of standardized work (regulation of manual labor):

• The basis of all operations on the gemba.
• Identifying areas of kaizen actions and consolidating improvements in new standards.
• Providing new workers with accurate and complete instructions.
• Prevent unnecessary operations from being performed.
• Guaranteeing quality and labor safety, ensuring the required production volumes and an acceptable level of costs.

Three elements of standardized work

1. Cycle time (time to produce one product or part)
2. Sequence of operations (assembly or manufacturing of products carried out in a certain time sequence)
3. Availability of standard buffer stocks (an absolute minimum of stocks that ensures the continuity of rhythmic and cyclical work).

Advice. If markings are made on the floor of the workshop that correspond to the sequence of procedures (for example, using arrows and numbered lines), then operators will complete the work faster and with better quality.

The introduction of standardized work makes it possible to identify and eliminate losses and improve production processes (Fig. 12).

Stage 10. Quality Assurance

Quality arises in the process of work. Control procedures do not create quality as such. Collective quality control is ineffective: “I process the products - you check the quality.” The self-monitoring procedure allows workers to verify how accurately production standards are being followed when producing products. The worker checks the quality of manufactured products at specified intervals (every hour) and enters the data into a self-control sheet. By checking the results of his work, he monitors the quality of the finished product and ensures that low-quality products do not enter the subsequent process (for more details, see and). Poka-yoke are devices built into machines and mechanisms that provide automatic error protection.

Stage 11. Equipment

The value of machines and mechanisms is determined not by the degree of wear or service life, but by the ability to make a profit. Enterprises must take care to extend the life of equipment. To ensure continued performance of machines, they must be cleaned, inspected and lubricated regularly. The cause of defects should be sought based on the 3G principle: gemba - a specific place, gembutsu - a specific defective object, genjitsu - specific conditions. Equipment availability is the proportion of time during which a line or machine is in working condition.

Stage 12. Kanban system

A kanban is a card that specifies which items should be removed, how many, and how those items should be produced. The subsequent process removes strictly necessary products in the required quantity and at the required time, the previous process produces only what was ordered from the subsequent process. Cards containing information about the withdrawal and transportation of materials and products are called withdrawal kanbans. Cards containing production instructions are called production kanbans. These two types of cards circulate between processes, ensuring their regulation. Kanbans are carriers of information as well as downstream process requirements.

In traditional manufacturing systems, products are “pushed” by a previous process into a subsequent production stage. Products are released according to a schedule based on forecast demand. This means that the previous production stage produces and moves items that were not ordered. With this approach, excess production is inevitable. The only way to eliminate losses caused by overproduction is to change the production system, i.e. move to producing only the necessary products in the required quantity and within the required time frame. Such a system can be compared to a supermarket, in which goods are put on the shelves only to replenish goods that have already been sold, in other words, after the subsequent process (the consumer) has withdrawn what is needed. The most important principle of such a system is the availability of products for which there is demand in the required quantity and at the required time.

Three functions of kanbans: automatic transmission of information - production instructions, integration of material and information flows, effective tool kaizen.

Conditions preceding the introduction of kanbans into practice:

• creation of continuous production
• batch size reduction
• smoothed production
• reduction of transport cycles and unification of routes
• continuous production
• addresses and storage locations
• type of packaging and types of containers

Rules for using kanbans:

• Every container should have a kanban on it.
• After the first item is removed from the container, the kanban is removed and placed in the kanban box/rack
• the subsequent process removes products from the previous process
• product release is carried out in the same sequence in which products are withdrawn by the subsequent process
• it is necessary to produce as many products as were removed by the subsequent process
• if there is a shortage of parts at a subsequent stage, you must immediately report this to the previous stage
• Kanbans should be put into circulation and their circulation monitored at the same production site where they are used
• Kanbans should be handled as wisely and carefully as money
• never pass on defective products to the next production stage

The introduction of kanbans should begin with the last production stage. Kanbans used at the final stage of production are called supply kanbans. In this case, kanban cards are also delivery orders. If the enterprise does not use delivery kanbans, then their function is performed by kanbans for the withdrawal of finished products. The role of the customer in this case is performed by the production planning department.

Once the finished product removal kanbans are attached to the parts containers, the assembly kanban becomes a production order to make new parts. Assembly kanbans in the order they are received (i.e., in the order parts are removed) are placed on a production order tracking board located at the beginning of the assembly line. This board is a visual management tool. The withdrawal kanban acts as an order for the movement of products and parts. Products that are withdrawn for production needs must be immediately replenished with the same ones (Fig. 13).

A production kanban is an order for the production of a specific product. Production kanbans are removed from containers immediately after parts are removed and moved to finished goods storage. The production kanbans are then placed in the order they are received on the production order tracking board. You can reduce the number of kanbans in circulation using kaizen actions.

Very important for synchronization production processes use a special red box as a visual guide. The main task control on the gem is the resolution of emergency and problem situations. Using red boxes helps identify bottlenecks in your kanban system and allows you to take immediate corrective action.

All production orders must arrive at the gemba in the form of kanbans. Not on the gem production plan in the traditional interpretation of this concept: the basis for production is demand at the next stage. The kanban must include the product name and number, part names and numbers, location, container type, number of items in the container, and registration numbers.

At the beginning of the implementation of kanbans, workers often do not understand the feasibility of their use; kanbans seem to them to be an additional burden. That's why it's important to initially explain the purpose of using kanbans, provide workers with clear instructions, and discuss the benefits of this tool for improving production. Kanbans are also a critical tool for implementing and maintaining just-in-time.

Stage 13. Interrelation and systematization of the stages of synchronized production

When implementing a synchronized production system, it is necessary to remember the interrelationship of the stages. An attempt to implement one separate stage without taking into account the relationships within the entire system will certainly end in failure (Fig. 15).