1. Concept

Lean production management is a brand-new production management mode that is driven by customer demand and centered on eliminating waste and continuous improvement, enabling enterprises to obtain cost and operational benefits with minimal investment. It is characterized by emphasizing the customer's requirements for time and value, organizing production activities that bring value to customers with a scientific and reasonable manufacturing system, shortening the production cycle, and significantly improving the ability of the enterprise to adapt to the ever-changing market.

Lean production is the optimal production method under the condition of multiple varieties and small batches. The implementation of lean production will bring huge benefits to enterprises, so it is known as the second production method revolution.

Today, with the continuous improvement of manufacturing and management technology, the meaning of lean production has surpassed the original TPS. After studying various management modes including lean production, the United States put forward a manufacturing enterprise strategy in the 21st century - agile manufacturing. It can be considered that lean production is the bridge to agile manufacturing. Agile enterprises refer to those enterprises that can make full use of the advantages of network technology, quickly realize self-adjustment to adapt to the changing competitive environment, and have agile and rapid response capabilities. Therefore, without the basis of lean production management, it is difficult for enterprises to achieve agile manufacturing.

To achieve lean production management, the most basic one is to eliminate waste. There are many wastes in the production and business activities of enterprises. To eliminate waste, we must first distinguish two basic components in enterprise activities: value-added activities and non-value-added activities.

2 categories

Lean production divides the production activities of enterprises into three categories according to whether they are value-added: value-added activities, activities that are difficult to eliminate without value-added, and activities that can be eliminated immediately without value-added. Lean production regards all non-value-added activities as waste, and proposes seven kinds of waste (Muda) in production, and the implementation of lean production must focus on eliminating these seven kinds of waste. For a long time, people have paid attention to the efficiency improvement of value-added activities and neglected to tap the potential of non-value-added activities. Research shows that only 10% of the time when materials enter a factory to leave the factory is value-added. The secret of successful lean production is to shift the focus of improving efficiency to non-value-added activities that account for 90% of the time.

3 value

The source of an enterprise's realization of value is the customer. Lean production proposes that the product value should be determined by the customer, and requires reviewing the enterprise's product design and production and operation process from the perspective of the customer, and identifying value-added activities and various wastes in the value stream. Enterprises should eliminate redundant functions and redundant non-value-added activities that customers do not need, and do not pass on additional expenses to customers, so as to achieve the most effective satisfaction of customer needs.

4 stagnation

Lean production regards all stagnation as waste, and requires the promotion of stagnant logistics operations, the decisive abandonment of those who cannot keep up with the progress, and the flow of various value-added activities, emphasizing the uninterrupted value flow. The traditional division of functions and mass production methods often block the value flow that should be activated, resulting in a lot of waste, such as a large backlog of work in progress, production capital occupation, reduced plant utilization, increased management costs, and batch quality risks. etc.

5 Premature overdose

Lean production believes that premature production and excessive production are waste, and should be produced on time according to the principle of demand pull. Demand-pull is to input and output according to the needs of customers (including downstream processes), so that customers can get the products they need at the exact time they need, just like picking what they need on the shelves of a supermarket, rather than putting users who don’t want to. What you want is forcibly pushed to the user. Due to the direct connection between production and demand, the pull principle eliminates premature and excessive investment, reduces a large amount of inventory and work in process, and greatly reduces the production cycle.

6 Value Streams

Lean production requires people to identify value streams, use JIT (just-in-time), one-piece flow and other methods to realize the continuous flow of value-added activities according to demand, and apply 5S, TPM, error-proofing, rapid production conversion and other methods to provide support and guarantee for value flow. The implementation of lean production is a never-ending process, and the result of its improvement must be the continuous elimination of waste and the continuous mining of value.

Lean production pursues perfect continuous improvement. Improvement is based on demand. It requires staff not only to do what they can do, but also to challenge what they should do, to become a improver rather than a person to be improved, and for the events to be improved Thoroughly investigate the truth of the incident. Before improving the equipment, improve the staff's work to ensure its adaptability to the improvement. After the improvement plan is determined, first confirm the safety and quality, otherwise the improvement will also become a waste.

7 Thought connotation

The ideological connotation of lean production can be summarized into five points, which are customer determination of value, identification of value flow, value flow, demand pull, and perfection. By understanding and applying these five principles of lean thinking, you have the recipe for success in lean manufacturing.

8 management principles

Principle 1: Eliminate the Eight Wastes

Eight wastes that are prevalent in businesses involve: overproduction, waiting time, transportation, inventory, process (process), movement, product defects, and neglect of employee creativity.

Principle 2: Focus on Process to Improve Overall Effectiveness

Management guru Deming said: "Employees are only responsible for 15% of the problems, and the other 85% are attributed to the system process". What kind of process produces what kind of performance. When improving the process, it should be noted that the goal is to improve the overall benefit, not the benefit of a local department. For the overall benefit of the enterprise, even at the expense of the benefit of a local department.

Principle 3: Establish uninterrupted processes to respond quickly

Establish an uninterrupted process, compress the invalid time that does not add value in the process as much as possible to shorten the time of the entire process, so as to quickly respond to customer needs.

Principle 4: Reduce Inventory

It should be pointed out that reducing inventory is only one of the means of lean production, the purpose is to solve problems and reduce costs, and low inventory requires efficient processes and stable and reliable quality to ensure. When many companies implement lean production, they think that lean production means zero inventory. Without first transforming the process and improving the quality, they just ask the following to reduce the inventory. As a result, it is conceivable that the cost has not been reduced, but has risen sharply, so they came to the conclusion. , Lean manufacturing is not suitable for my industry, my business. This misunderstanding needs to be avoided.

Principle 5: High quality throughout the process, right the first time

Quality is manufactured, not tested. Inspection is only an after-the-fact remedy, which is costly and cannot guarantee error-free. Therefore, quality should be built into design, process and manufacturing to establish a quality assurance system that will not go wrong, right the first time. Lean production requires low inventory and uninterrupted flow. Just imagine that if there is a problem in any link, all the following ones will be stopped. Therefore, lean production must be based on the high quality of the whole process. Otherwise, lean production can only be empty talk.

Principle 6: Pull production based on customer demand

The original intention of JIT is: when needed, only produce according to the required quantity, and production and sales are synchronized. That is, to produce at the rate of sales, so that the logistics can be kept in balance, and any production that is too early or too late will result in losses. In the past, Toyota used the "Kanban" system to pull, supplemented by ERP or MRP information system, it was easier to achieve external material pull.

Principle 7: Standardization and Job Innovation

The role of standardization is self-evident, but standardization is not a restriction or restraint, but to fix the best practices in the enterprise, so that different people can do the best, and maximize the effectiveness and efficiency. . Moreover, standardization is not rigid and immutable, and standards need to be constantly innovated and improved.

Principle 8: Respect and empower employees

Respecting employees means respecting their wisdom and abilities, providing them with a stage to give full play to their ingenuity, and doing better for the company and themselves. In Toyota, employees practice self-management and act on their own within the scope of the organization's responsibilities. They don't have to worry about being punished for mistakes at work. Errors must have their own internal reasons. . Therefore, a lean enterprise employs "a whole person", while a non-lean enterprise only employs "a pair of hands".

Principle 9: Teamwork

Flexible team work has become one of the most common organizational forms in a lean enterprise, where the same person sometimes belongs to different teams at the same time and is responsible for different tasks. The most typical team work is Toyota's new product development plan, which is driven by a large team with members from various departments, such as marketing, design, engineering, manufacturing, procurement, etc., they are in the same team Working together, the time to launch of new products is greatly shortened, with higher quality and lower cost, because many problems are fully considered from the beginning and solved by professionals before they cause trouble.

Principle 10: Meet Customer Needs

To meet customer needs is to continuously improve customer satisfaction. It is quite short-sighted to sacrifice customer satisfaction for a little immediate benefit. Toyota never talks about these words, and always implements it with practical actions. Although the supply of products is in short supply, Toyota never blindly expands the scale before all preparations are made, and maintains a stable and pragmatic style to win the respect of customers. Toyota's financials show that its annual profit growth rate is almost twice as fast as its sales growth rate, and the annual growth rate is fairly stable.

9 major companies

The management method that Chinese enterprises are accustomed to is: focus only on results, not on processes. The long-term focus is on improving quality, reducing costs, shortening lead times and improving production efficiency.

10 Management Status

Basic "5S" management aspects

There are still deficiencies in sorting and rectification, there are many problems at the scene, and the management of fixed positions is chaotic.

Virtually no visual management, unclear visual management, lack of signage, and time-wasting item hunting. When there is a problem, it cannot be found in time.

The standardized management of standards is not enough, the production work lacks standardization, the operating standards are not perfect, and the standard formulation is unreasonable.

The equipment maintenance mechanism is not perfect, there are many failures, and the number of failures and shutdowns is relatively frequent.

Production operations and production sites

Some personnel have backward production concepts, and have not formed an order-centric production operation concept.

The production statistics and analysis system is not perfect, and it is difficult to effectively evaluate the status of the company's production system.

The production mode results in large intermediate work-in-progress, which occupies a large amount of capital and production space.

The color paste configuration and sample trial production are not standardized, resulting in a lot of wasted production time.

The continuous adjustment of the delivery time has covered up many problems in the manufacturing process, and the problems in the production cannot be solved in time, resulting in a slow system response.

There is a lack of working standards on site, and the staff's work is irregular and random, resulting in poor quality.

There is no visual tool for standard operation management on site, management is chaotic, and the on-site logistics management lacks standards, resulting in logistics chaos.

quality management

The quality assurance system is not sound enough, and inspection systems such as parts inspection, manufacturing inspection, QC inspection, and self-inspection should be strengthened.

The quality process control ability is weak, resulting in a lot of quality cost loss.

Visual quality control, prior quality engineering diagnosis, preventive management, and ex post quality countermeasure improvement are not adequately done.

The quality data analysis is not thorough, and it is impossible to improve the operation behavior.

Management atmosphere and personnel capacity:

The quality and management ability of grass-roots managers need to be improved, and management skills need to be strengthened, especially the ability to identify problems, solve problems, and deal with them alone. At the same time, training in advanced management concepts is required.

It is necessary to further create an improved climate atmosphere and carry out environmental rendering, such as: employee training, slogans, status boards and other methods to improve the environment, starting from the improvement of employee quality, and carry out improvement proposal activities, so as to improve the overall level of the company.

11 Features

Pull just-in-time production

Taking the needs of end users as the starting point of production, emphasizing logistics balance, pursuing zero inventory, and requiring that the parts processed in the previous process can immediately enter the next process.

Organizing production lines relies on a form called Kanban. That is, the information of the demand from the next to the next is transmitted by the kanban (the form of the kanban is not limited, the key is to be able to transmit information). The rhythm in production can be manually pre-controlled and controlled, but the key is to ensure the balance of tough flow in production (for each process, it is to ensure the timely supply of subsequent processes). Due to the use of pull production, the planning and scheduling in production are essentially completed by each production unit itself, and centralized planning is not adopted in form, but coordination between production units during operation is extremely necessary.

Total Quality Management

Emphasize that quality is produced rather than inspected, and the final quality is guaranteed by the quality management in production. The inspection and control of quality in the production process are carried out in each process. Focus on cultivating the quality awareness of each employee, pay attention to quality inspection and control during each process, and ensure that quality problems are found in time. If quality problems are found in the production process, according to the situation, production can be stopped immediately until the problem is solved, Thereby ensuring that there will be no major quality accidents and invalid processing of substandard products.

For the quality problems that arise, the related technical and production personnel are generally organized as a group to work together to solve them as soon as possible.

team work

Team work. Every employee is not only executing orders from superiors at work. What is more important is to actively participate in decision-making and auxiliary decision-making. The principles of organizing teams are not completely divided according to the administrative organization, but mainly according to the relationship of the business. Team members emphasize one specialization and multiple abilities, and are required to be familiar with the work of other staff members in the team to ensure smooth work coordination. The evaluation of team members' work performance is influenced by the evaluation within the team. (This is closely related to Japan's unique personnel system.) The basic atmosphere of team work is trust, which is based on a long-term supervision and control, and avoids auditing of each step of work to improve work efficiency. The organization of the team is changing. Different teams are established for different things. The same person may belong to different teams.

concurrent engineering

Concurrent Engineering. During the design and development of the product, the conceptual design, structural design, process design, final demand, etc. are combined to ensure that the required quality is completed at the fastest speed. The work is done by the related project team. During the process, team members arrange their own work, but they can provide feedback on a regular basis or at any time and coordinate and solve problems that arise. Feedback and coordination of the entire project in accordance with appropriate information system tools. Utilize modern CIM technology to assist the parallelization of project processes during product development and development.

12 Implementation steps

1. Select key processes to improve

Lean manufacturing is not achieved overnight, it emphasizes continuous improvement. The key process should be selected first, and strive to establish it as a model line.

2. Draw a value flow diagram

A value stream map is a method used to describe the flow of logistics and information. After drawing a value stream map of the current state, a Future Lean Vision can be drawn. In this process, more icons are used to represent continuous processes, various types of pulling systems, balanced production and shortening of tool change times, and the production cycle is subdivided into value-added and non-value-added times.

3. Conduct continuous improvement workshops

The Lean Vision has to be put into practice, or a well-planned diagram will be just a piece of paper. What is included in the implementation plan (What), when (When) and who will be responsible (Who), and set up review points in the implementation process. In this way, all employees participate in the full-staff productive maintenance system. Under the guidance of the value flow map and the lean vision, each independent improvement project in the process is given a new meaning, so that the employees are very clear about the meaning of implementing the project. There are several ways to continuously improve the production process: eliminate quality inspection and rework; eliminate unnecessary movement of parts; eliminate inventory; rationalize production planning; reduce production lead time; eliminate downtime; improve labor utilization.

4. Create a corporate culture

While significant improvements taking place on the shop floor can trigger a subsequent series of corporate culture changes, it is clearly inappropriate to assume that positive cultural change can be automatically established and driven as a result of improvements in shop floor layouts and production operations. realistic. Cultural change is more difficult than improvement on the production site, both must be done and complement each other. The implementation experience of many projects has proved that the key to the success of the project is the combination of the improvement of production methods and the evolution of corporate culture by company leaders.

The transformation of traditional enterprises to lean production can not be accomplished simply by using corresponding "kanban" tools and advanced production management technology, but must change the concept of all employees. The reason why lean production originated in Japan, not in the United States, is precisely because the corporate cultures of the two countries are quite different.

5. Promote to the entire enterprise

Lean manufacturing utilizes a variety of industrial engineering techniques to eliminate waste and looks at the entire production process, not just individual or several processes. Therefore, the success of the model line should be extended to the entire enterprise, so that the operation process is shortened, and the push production system is replaced by the customer-oriented pull production system.