The hottest lean production 3 features 5 steps 7 w

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Lean production has three characteristics, five steps, seven wastes, and ten words

starting from the classic lean system, the three characteristics of lean production are refined. Since MIT professors published the book "machines that change the world" in the early 1990s, lean production has spread all over the world and become a management method for many enterprises to learn from. So, what are the significant characteristics of lean production? Starting from the classic lean system, this paper refines the three characteristics of lean production, which are pull production, waste elimination and self-improvement. These three characteristics should help us quickly understand the connotation of lean production, and also have a certain reference value on how to implement lean production

1. Pull production

definition: the so-called pull production refers to that this process can be produced only when the next process is required. The Chongqing project has industrial strategic significance, and there is a link between processes, which restricts and balances each other

analysis: form a back-up mechanism to ensure smooth production

backward force mechanism: because processes are interconnected for pull production, any process (link) problem will make production unsustainable. This is also an important reason why many enterprises have not achieved results in the implementation of pull production, but have lower efficiency and affect the production progress. A small proposal is that when implementing lean, don't rush to pull. The small body of the enterprise may not be able to stand the strict pull, and it will hurt if you pull

the process (link) problems include: equipment failure, imperfect process, unskilled staff operation, defective products, etc. the backward mechanism formed by pull production forces these problems to be eliminated to the greatest extent. Only in this way can production be carried out smoothly and reflect the great value of pull production

2. Eliminate waste

definition: eliminate waste, that is, eliminate various obstacles that affect smoothness in the production process

analysis: eliminating waste is regarded as the core of lean production, because pull production can be carried out smoothly only by eliminating various obstacles in the production process. Even if pull production is not implemented, eliminating waste itself has a significant contribution to improving production efficiency. Another major role of eliminating waste is to promote the transition of production operations from labor-saving to fewer people

management of seven wastes: in lean production, there are seven wastes summarized, which are: ① transportation waste; ② Action waste; ③ Processing waste; ④ Bad waste; ⑤ Waiting for waste; ⑥ Overproduction; ⑦ Inventory waste

among them, transportation waste, action waste, waiting waste and processing waste can generally be eliminated through industrial engineering methods, which is the common place between lean production and industrial engineering

bad waste is an explicit waste, and the cost loss caused by bad is clearly visible. The elimination of undesirable waste should not be limited to lean production tools (three manifestations, five whys, total quality management, all staff preventive protection, etc.), but can be combined with six sigma tools for project-based improvement. Upgrade and replace the equipment or process when necessary

pull production interacts with the elimination of excess production and inventory. On the one hand, the implementation of pull production itself can eliminate excess production and inventory. On the other hand, pull production can be better implemented by eliminating excess production and inventory. In terms of specific measures, balancing the production line, making production plans, connecting supply chain enterprises, and setting the minimum inventory can effectively improve the inventory of raw materials and finished products

3. Definition of automation

generally refers to the operation mechanism that the equipment can automatically identify errors and automatically stop; It also refers to avoiding mistakes through the cooperation between people and equipment

analysis: self identification can improve the yield of products because of the device that automatically identifies and automatically stops. The more obvious function of self localization is to reduce the number of people, liberate people, and one person can work on multiple machines. With fewer people doing more work, there is no doubt that efficiency will be greatly improved

the tools and concepts associated with automation include preventive protection for all staff, rapid mold change, line stop mechanism, mindless method, training of multi skilled workers, etc


through the above analysis of the three characteristics of lean production, we can clearly see that the basic management of enterprises is very important, including the implementation of on-site 5S, total quality management, production line equalization, good improvement culture, etc. Only by doing a good job in basic management, and then taking the elimination of waste as the core and starting point, we can promote the pull production mode with our own enterprise characteristics, and improve the self-improvement degree of the enterprise through long-term accumulation, so as to finally realize the lean production of the enterprise

after publishing the book "machines that change the world", lean experts Womack and Jones published the book "lean thinking" in 1996 through interviews and in-depth research, which was revised and republished in 2003, refining and summarizing the five steps of lean practice

how can we implement lean production with lean five steps? Completely eliminate waste, feed according to the system status with the minimum buffer cost, limit the number of WIP, and let the customer drive the value, smooth the value flow, and deliver the value

first, define/identify value

the key starting point of lean practice is value, which can only be determined by customers. Providing the wrong products or services is a waste

please note that lean is not the goal of the manufacturing system, and value is the goal of the manufacturing system. The value perception of customers has nothing to do with our costs and efforts

we should take customer value cognition as the starting point of lean, form a decisive competitive advantage, and take it as the goal of developing manufacturing system. If the goal is wrong, the subsequent development of the manufacturing system will be a waste

in many cases, competitors are unaware of the problems of industry or operation mode, and examining the problems caused by customers in the industry is the starting point to identify the decisive competitive advantage

second, identify the value stream

the value stream of a specific product contains three key management tasks, which are:

① problem solving tasks in the whole process from concept, product planning, design, to production

② information management tasks in the whole process from receiving orders, making production plans to delivery

③ the task of material transformation from raw materials to finished products and delivered to users

value stream analysis can show three activities along the value stream:

steps that can create value, such as machining processes that change physical shapes

although it does not create value, it is an inevitable step under the existing technology and production conditions. For example, in order to ensure quality, the welding joint should be inspected (called type 1 waste)

steps that do not create value and can be removed immediately (called type 2 waste), such as deburring

III. flow

once the value has been accurately determined, the value flow chart of a specific product has been completely formulated, and the obvious waste steps have been eliminated. The time has come to implement the third step of lean thinking, so that the steps that remain and create value can flow

in response to the impact of fluctuations, we should make good use of buffers, such as time, capacity or inventory buffers, balance the flow to absorb the impact of fluctuations, so as not to break when pulling

IV. pull

the simplest meaning of the word pull is that there is no upstream process or enterprise to produce products or provide services before downstream customers put forward requirements

advantages of using pull system: reducing cost: low number of WIP and less rework; Improve quality: there is pressure to pursue internal quality and better detection ability; Better customer service: short lead time and predictable output; Greater flexibility: only when the system state allows the workpiece to be processed, the workpiece will be pulled into the system

v. perfection

continuous fundamental and continuous improvement requires learning and observing value flow, value flow, and value driven by customers, so that perfection becomes a clear and visible image, so that people can see the improvement goal, and make this goal realistic for the whole enterprise. Concentrate on eliminating waste, reducing volatility, shortening lead time, starting from demand, solving problems, and don't let inertia become a constraint on system progress

in the process of perfect improvement, there will be a conflict between encouraging improvement and reducing employees. Employees work hard to improve, but they are cut because of efficiency improvement. In this way, employees will not be relieved to devote themselves to improvement. It is necessary to moderately increase competitiveness, but it is more necessary to reassure employees, establish a negative corporate image, and share the results of improvement

conclusion: managers should correctly identify and define value, establish their own decisive competitive advantage, break the market bottleneck, make more money, and make their foundation evergreen

stand on the shoulders of giants and quickly and effectively build the framework of lean production. Perhaps the integration of TOC, lean and Six Sigma is more effective. Take TOC as the locomotive to pull the system macroscopically, use the magnifying glass of Toyota field management method to eliminate waste, and use the microscope of Six Sigma to reduce fluctuations, so that the system can run lean production with the minimum buffer cost

transportation waste, one of the seven wastes

performance: too many people move around; Special transportation is needed to realize the connection between processes; Excessive transportation

reasons: inefficient workshop layout, too large equipment, unsmooth production, etc

countermeasures: put an end to island production, reasonably and compactly arrange the process, let the operation flow and form a rhythm, so that there is no need for too much transportation

the second of the seven wastes, action waste

performance: the operation action is not coherent, the range is too large, the turning angle is large, bending down, the action is repeated or redundant, forming waste

harm: action waste will have a negative impact on production efficiency, quality and personnel safety

countermeasures: from the perspective of ergonomics, reasonably use industrial engineering techniques to optimize the layout of the worktable and standardize the operation

processing waste, the third of the seven wastes

performance: excessive machining allowance, unnecessary machining accuracy, redundant product functions, repeated inspection and packaging, etc

reason: self righteous work, not customer value oriented

countermeasures: examine the existing processes by omitting, replacing, reorganizing or merging; Accurately grasp customer needs, optimize operation standards and the connection between processes. (just right is beauty)

the fourth of the seven wastes. Bad waste

performance: bad products produced in the production process

reasons: improper manual operation, improper process setting, improper use of materials, unclear quality standards, etc

countermeasures: ① ensure that the operation instructions and inspection standards meet the product characteristics and customer needs. ② Find defects at the first time through first sample inspection, patrol inspection, self inspection and mutual inspection; ③ The formulation pole sets the zero return oil acceptance limit sample between the two seals and visualizes the inspection standard, so that employees can easily understand the standard. ④ Appropriately use the fool proof method to set error proofing

five of the seven wastes waiting for waste

performance: personnel (and equipment) are waiting; Or, sometimes busy, sometimes idle unevenly

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