Improvement On Production Material Control Of A Lean Manufacturing Workshop

Based on value stream map of lean manufacturing, this thesis analyses the current status of the production material control system in a plant, and find that in the manufacture plant the real accumulated value added time is only 726.6sec, but the non-value added time is 28,800sec, such that the value–added rate is only 2.46%. Non-added value activities mainly take place on the process storage in about 9 locations, and the storage is as high as 2220pcs so as to take a lot of time on material handing, protract the production lead time to 32hours, and worsen the discrepancy for takt time between working procedure. With in-depth study, many problems are found on production flow, facility layout, WIP management and Kanban system. By recalculating standard cycle time and production capacity, and using the work combination table, current processes are combined and optimized, such that the balance of work line is improved, the number of the operators is reduced, the work procedure diagram is improved, and thus production flow is optimized and production synchronization and equilibrium are developed. Based on the concept of"one piece flow", the thesis makes effort in improving current facility layout as follows: the machining cells use the air fleet layout, the layout takes the form of"—"like arrangement, while the assembly cells take the form of"U", such that more flexibility is obtained, and"one piece flow"production is established. Via decreasing the number of WIP spots and establishing the maximum and minimum levels of WIP, and establishing the pull system between WIP spots, the changeover time is shortened, and the quantity of WIP are reduced greatly, together with"one piece flow"layout, the management of WIP is developed greatly; Via the application of kanban system management, the analysis on production material flow pulling, material container standardization, improvement is made on material tool and establishing material deliver chart such that the kanban system is established. Finally, it is found that production flow is optimized, flexibility of facility layout is improved, the quantity and spots of WIP is reduced greatly, and a great improvement has been made on the production material control system. The thesis also analyses the value stream map for production material control system after improvement , and finds that the real accumulated value added time is still 726.6sec,but the non-value added time is reduced to 10372sec, the value–added rate reaches 6.55%, with an increase of 4.09% .