求翻译：　　材料采购决策主要是对材料的采购时机、采购地、采购次数等问题做出选择。材料采购时机是影响材料费用的重要因素，采购时机恰当，将节省大量材料成本，反之会加大材料成本投入。是什么意思？

　　Material procurement decision mainly on the purchase time, number of procurement, procurement of materials to make a decision on such issues. Timing is an important factor affecting the cost of materials materials procurement, procurement time appropriate, substantial savings in material cost, instead will increase the cost of material inputs.