发布时间 : 星期一 文章SAP MRP更新完毕开始阅读
MRP
屠宰系 杀猪专业
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9
屠宰学学士Ron
我估计 你真的认错人了
MRP
屠宰系 杀猪专业
2、净需求计算(书本上讲的很粗略，也没有具体例子，这是我在yahoo上搜到的，供参考)
FOR EXAMPLE:
The Master Production Schedule shows we have to make 400 scissors during the 3 rd week, in the 4 th week 600, in the 6 th week 800, and in the 7 th week 300 scissors.
We will name (GR) Gross Requirements to the demand of fabrication of the products, the final products (in this case the scissors) correspond to the quantity appeared in the MPS. To the intermediate products (in this case the screws) you have to multiply the necessary quantity to make the final product with its demand.
Gross Requirements of the MRP
10
屠宰学学士Ron
我估计 你真的认错人了
MRP Inventory Master File
屠宰系 杀猪专业
The file indicated us that we have since the first week 550 scissors in stock, also it indicates that the security stock do not have to be less than 50 scissors.
We will name Availability (A) to the initial stock of the final product we have to satisfy the before mentioned necessities.
We Will name Security Stock (SS) to the final quantity of the final product that cannot be use to satisfy the necessities.
We will denominate Net Requirements (NR) to the quantity that we really need to satisfy the Gross Requirements (GR), taking into account the Availability (A) and the Security Stock (SS), the calculations will be the following:
1. If the availability is more than 0 , NR = GR-A+ SS 2. If the availability is equal to 0 , NR = GR
Net Requirements of the MRP
Week 1: Gross Requirements are invalid, the availability is of 550 units, inside the security stock is 50, and therefore if we do not have Gross Requirements there are not also Net Requirements. GR = 0 A= 550, SS = 50 NR = 0
Week 2: the same as the week 1, so we have an Availability of 550 units and the Security Stock is 50 units.
Week 3: The Gross Requirements are 400 units, but we have an Availability of 550 inherited of the last week, so we can satisfy the 400 units with the 550 available and we make sure that 50 we have 50 units for the Security Stock.
NR = GR- A + SS; NR = 400- 550 + 50; NR = - 100
It is important to realise that the result is negative, that means that we do not need to make more scissors, because there are 150 available. 550-400 = 150
11
屠宰学学士Ron
我估计 你真的认错人了
MRP
屠宰系 杀猪专业
Week 4: We need to make 600 scissors but we only have 150 units that were left the weeks before, so the Nets Requirements are:
NR = GR- A + SS; NR= 600-150+50; NR = 500
We have to make during the 4 th week 500 scissors; we ensure that the Security Stock has 50 units. Week 5: The GR are invalid, we do not need to fabricate more because the NR are also invalid. Week 6: The Gross Requirements are 800 units, the Availability is invalid so, NR= GR, NR=800
We have to fabricate 800 units during the 6 th week, and our security stock is 50 units. Week 7: The same as in the week 6, our Net Requirements are 300 units, NR= GR, NR=300
Net Requirements of the MRP 其实这个例子很简单易懂，运用两个公式算净需求：
1. If the availability is more than 0 , NR = GR-A+ SS 2. If the availability is equal to 0 , NR = GR
3、replenishment lead time: 包括三个部分，如图：
12
屠宰学学士Ron
我估计 你真的认错人了