tailieunhanh - [Psychology] Mechanical Assemblies Phần 9

Tâm lý học: Nghiên cứu những quy luật chung nhất của thế giới tinh thần con người trong sự vận động tương tác với thực tại khách quan (tâm lý đại cương) và những quy luật riêng biệt trong đời sống. | 444 16 ASSEMBLY SYSTEM DESIGN pulling work from upstream stations based on customer orders rather than pushing work downstream based on a preplanned schedule. The aim is to produce what is wanted when it is wanted and where it is wanted. To accomplish this the system is run by passing orders upstream in the form of kanbans. Kanban is the Japanese word for ticket but the kanbans act like money in the sense that they are used by downstream stations to buy parts from upstream stations. For this reason if the orders are entered at the very end of the line a signal representing what was just made will propagate upstream causing the same things to be made over and over. In order to guarantee that the actual mix of incoming orders is reflected upstream and to combat the variations caused by model mix Toyota employs production smoothing or load leveling which are discussed next. Furthermore as discussed in Section the order stream may be inserted in the middle of the line instead of the very end. . Production Smoothing or Load Leveling Orders from customers do not arrive in the best sequence for production. Suppose the plant makes car A and car B among others. Assume car A takes much less than the average time to make while car B takes much longer. If 10 orders each for car A and car B arrive it may disrupt the line to schedule them each in a solid batch. If the factory operates at a standard pace operators working on a solid batch of 10 A s will have time left over and nothing to do. On the other hand operators working on a solid batch of 10 B s will fall behind. It is better to interleave these orders as ABAB. so that over these 20 cars the operators will take about the average time. Another kind of smoothing is also pursued. Suppose the plant receives orders for sedans hardtops and wagons in the following proportions 50 sedans 25 wagons and 25 hardtops. If these different cars use some different parts then demand for the parts will vary. As in other .