The Application Of Lean Production In A Improving Project Of Keyboard Production Shop Floors

With keyboard business continuously growing up, Sai Li Hua company introduces and implements lean manufacturing methodology, and requires its production shop floors to eliminate waste, reduce production cost and improve productivity for increasing their market competition strength.The keyboard production process of Sai Li Hua company was studied in this paper. Through analyzing current production status of the keyboard production shop floors and collecting data of the production site, a current state value stream mapping (VSM) was carried out. Base on the value stream mapping analysis, the waste phenomena of process activities were identified. On the basis of the above, a future state value stream mapping was figured out to reduce the non-value added time and balance the operating time of keyboard assembly line. This paper was focusing on two improvement activities, one is built up Kanban system substituted with original MRP system on managing WIP and finish products inventory, the other is balancing of keyboard assembly line.After introduced the Kanban system on managing WIP of injection molding part, the original push production system was replaced by pull production system compliance to keyboard assemble requirements. The KanBan system utilized supermarket concept constructing on a pull system. After implemented KanBan system, the WIP of injection molding parts was reduced from 2 ~ 3 days to around 1 day. Meanwhile, to facilitate Kanban system implementation and reduce WIP, this paper also studied quick tooling change over technology in molding injection tooling change over practice.In study of keyboard assembly line, working Study technology was utilized to calculate the standard working time and production cycle time of each process. Base on above investigation, the original operator's usage is quite low. (ie, some working station even only have 60% labor utilization). At the same time, a process analysis method was used to study the WIP and transportation of each workstation. The analysis result pointed out waiting time is too long, total waiting time almost occupied about 92% production time. The ECRS (Eliminate, Combine, Rearrange, and Simplify) and 5W2H technology were used to combine the work procedures and reduce waiting time of WIP and eliminate unnecessary transportation. It reduces 52% waiting time after improvement and also cut operator numbers.After implementing lean production of keyboard production shop floors, the lead time of the shop floors reduced 18%, The WIP was reduced 40%. The productivity efficiency was improved around 23% and labor usage increased about 19%. The lean production project was a good start for the continuous improvement activities and established a basis of all-round lean production in the whole company.