Analysis and introduction of the hottest lean prod

2022-10-19
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Analysis and introduction of key points of lean production

in the manufacturing industry, many of us believe that "lean" is just in time production JIT. The most popular and popular saying abroad is: lean is to eliminate all waste. Some people also use terms such as "synchronous manufacturing s m" and "flow manufacturing F M". The goal of lean thinking is to "create perfect value for users with perfect process." These statements are reasonable, and they all try to describe this revolutionary idea in the most lean language. "Lean thinking is the integration of people, process and technology" is a more comprehensive and serious understanding

according to the viewpoint of "integration of process, people and technology", a comprehensive understanding of lean thinking will help enterprises grasp the key points of establishing lean enterprises and have better operability. For the transformation from traditional production enterprises or mass production enterprises to lean production enterprises, there are mainly the following forms in manufacturing:

1. Improve the production process

lean production uses traditional industrial engineering technology to eliminate waste, focusing on the whole production process, not just individual or several processes

(1) eliminate quality inspection links and rework. If the product quality can be 100% guaranteed from the design scheme of the product to the production line of the whole product, then the phenomenon of quality inspection and rework will naturally become redundant. Therefore, the idea of "error protection" must be run through the whole production process of 130 stone building sealant, that is, from the beginning of product design, quality problems have been taken into account to ensure that each product can only be processed and installed in a correct way, so as to avoid possible errors in the production process

(2) eliminate unnecessary movement of parts. Unreasonable production layout is the root cause of parts moving back and forth. In workshops organized in the form of process specialization, parts often need to be moved around in several workshops, resulting in long production lines, long production cycles, and occupying a lot of WIP inventory, resulting in high production costs. By changing this unreasonable layout and having been put into use, the equipment required for the production of products should be arranged according to the processing sequence and be as compact as possible, which is conducive to shortening the transportation route, eliminating unnecessary moving of parts and saving production time

(3) eliminate inventory. Taking inventory as a solution to the urgency of production and sales is like drinking poison to quench thirst. Because inventory will cover up many problems in production, will also grow the inertia of workers, and worse, will occupy a lot of money. In lean enterprises, inventory is considered the biggest waste and must be eliminated. The effective measure to reduce inventory is to change "batch production and queuing supply" into one piece production flow. In the single piece production process (1) the size and quantity of the 'phase' of GH2132 alloy after heat treatment affect the strength of the alloy. Basically, only one production part flows between the processes, and the whole production process will always flow with the single piece production process. Ideally, there is no WIP inventory between adjacent processes. To realize the single piece production process and maintain the fluidity of the production process, we must also save any link costs and achieve the following two points:

synchronization - in the uninterrupted continuous production process, we must balance each process in the production unit and require that each operation take roughly the same time to complete

balance - reasonably arrange the work plan and staff to avoid the working load of a process being too high and too low. However, in some cases, a certain amount of WIP inventory must be kept, which depends on the handover time of the two adjacent processes

to implement the measures of single piece production process, synchronization and balance, the goal is to match each operation or group of operations with the single piece production time (tact time) of the production line. The production time of a single product is the production time required to meet the needs of users, and it can also be regarded as the beat or rhythm of the market. When production is strictly organized according to tact time, the inventory of finished products will be reduced to a minimum

2. Improve production activities

only continuous improvement of the production process is not enough to achieve lean production, but also further improve individual activities in the production process to better cooperate with the improved production process. In the case of no or little inventory, the reliability of the production process is very important. To ensure the continuity of production, we must reduce the production preparation time, machine maintenance, downtime of waiting materials and the generation of waste products

(L) reduce production preparation time. The general way to reduce the production preparation time is to carefully do all the preparation activities before starting the machine and eliminate various hidden dangers that may occur in the production process

a list each element or step of the production preparation procedure

b, identify which factors are internal (need to shut down to deal with); What are the external factors (which can be handled in the production process) (implement smed rapid line change method)

C. try to change the internal factors into external factors as much as possible

d. use industrial engineering methods to improve technology, simplify all internal and external factors that affect production preparation, and improve efficiency

(2) eliminate downtime. Total production maintenance (TPM) is the most powerful measure to eliminate downtime, including routine maintenance, predictive maintenance, preventive maintenance and immediate maintenance

a. routine maintenance - the maintenance activities performed by operators and maintenance workers every day require regular maintenance of the machine

b, predictive maintenance - use the measurement method analysis technology to predict the potential failure, so as to ensure that the production equipment will not cause time loss due to machine failure. Its significance lies in preparing for a rainy day and taking precautions

c, preventive maintenance - prepare files for each machine and record all maintenance plans and maintenance records. Every part of the machine should be thoroughly and strictly maintained, and the parts should be replaced in time to ensure that the machine does not have unexpected failures

d, immediate maintenance - when there is a fault, the maintenance personnel should come at once, on call, and deal with it in time

in the continuous production process, there is little inventory between the two processes. If the machine breaks down, the whole production line will be paralyzed. Therefore, eliminating downtime is of great significance to maintain continuous production. The goal of TPM is zero defects and no downtime. To achieve this goal, we must strive to eliminate the root cause of the failure, rather than just dealing with the symptoms of daily performance

(3) reduce waste products. Pay close attention to various phenomena that produce waste products (such as equipment, staff, materials and operation methods), find out the root causes, and then solve them thoroughly. In addition, those measures to eliminate rework are also conducive to reducing the generation of waste products

3. Improve the labor utilization rate

improve the labor utilization rate in two aspects, one is to improve the direct labor utilization rate, the other is to improve the indirect labor utilization rate

the key to improving the direct labor utilization rate is that one person is responsible for multiple machines or can adapt to multiple positions (one job, multiple abilities). This requires cross training for operators. The purpose of cross training is to enable operators on the production line to adapt to any type of work on the production line. Cross training gives workers great flexibility to coordinate and deal with abnormal problems in the production process. The premise of realizing one person with multiple machines or one work with multiple functions is to establish a work standardization system. Work standardization is to determine the most effective and repeatable method by studying a large number of work methods and actions. When working, employees must strictly follow the standardization. Its significance lies not only in the improvement of the utilization rate of direct labor, but also in the improvement of product quality. Because the adoption of a series of technical measures such as error protection and waste prevention ensures that each operation can only be carried out according to the only correct method

installing automatic detection devices on production equipment can also improve the utilization rate of direct labor. The production process is closely monitored by the automatic detection device from beginning to end. Once any abnormal conditions are detected in the production process, an alarm will be given or the machine will be shut down automatically. These automatic detection devices have replaced the activities of quality detection workers to a certain extent, eliminated the causes of quality problems, greatly reduced rework, and naturally improved labor utilization

the indirect labor utilization rate increases with the improvement of production process and the elimination of inventory, inspection, rework and other phenomena. Those measures that are conducive to improving the direct labor utilization rate can also improve the indirect labor rate. The human and material resources consumed in inventory, inspection, rework and other links can not increase the value of products, so these labor are usually regarded as indirect labor. If the indirect activities that cannot add value in the product value chain are eliminated, the indirect costs caused by these indirect activities will be significantly reduced, and the labor utilization rate will be correspondingly improved

in a word, lean production is an endless process of excellence. It is committed to improving the production process and every process in the process, eliminating all activities that cannot increase value in the value chain as far as possible, improving labor utilization, eliminating waste, and producing according to customer orders while minimizing inventory

lean is a new corporate culture, not the latest management fashion. The transformation from traditional enterprises to lean enterprises cannot be achieved overnight, which requires a certain price, and sometimes unexpected problems may occur, so that those who are enthusiastic about traditional production methods and skeptical of lean production can give one reason or another to refute. However, most of those enterprises that unswervingly follow the path of lean can recover all the transformation costs and enjoy the benefits of lean production within six months, or even less than three months. (end)

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