| The mould factory belongs to Job Shop and is a kind of workshop for manufacturing special products of different processing routes. The mould manufacture scheduling based on due date is a problem of how to schedule operation processing sequence to minimize tardiness. In this thesis, we discuss several important aspects of this problem first, including its concept, feature of data and problem of the algorithms in existence. The mould manufacture scheduling based on due date is the NP hard problem. It is impossible to find the optimal solution when the problem's scale is very large. So the heuristic methods are often applied to job shop scheduling such as priority rule method and special algorithms.The mould manufacture scheduling is based on the Optimized Production Technology considering its application in practice and its situation. At the same time, it also adopts the dispatching rules, such as SPT (Shortest Processing Time), EDD (Earliest Due Date) and so on. The method can ensure the delivery on time and decrease the semi-manufactured goods. The algorithm doesn't need to balance the capacities of the machines but the machines are regarded as the key machines and the general machines. When scheduling, the key machines are critical to be considered. In order to increase theefficiency, we need adopt different scheduling methods ahead and behind the key machines, namely pulling and pushing method. We also put forward a rolling scheduling in mould factory in order to calculate the capacities of the usable machines. This method can tell dispatcher ahead whether the shop accepts a new order or not.We developed a scheduling software module for mould factory based on the algorithm that is put forward in this thesis. The module calculates quickly and we get satisfactory results. At the same time,IVthe enterprises that are similar to the mould factory can use it for reference and for further research and this thesis provides a new method. |
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