Assembly Scrap in iPPE
Definition
Scrap that is expected to always arise during manufacture of a material with Integrated Product and Process Engineering (iPPE) when the material is used as an assembly. For materials manufactured with iPPE, assembly scrap is specified in the production version in the iPPE access object as a percentage. The assembly scrap therefore depends on the production version. This assembly scrap is calculated in iPPE as follows:
Assembly Scrap = Input Quantity * (Scrap Factor/100)
Lot size (yield) = Input quantity (total quantity that must be used) – scrap = Input quantity (1 – scrap factor/100)
Use
An assembly is a set of components that are installed as a unit in the product being manufactured. An assembly can itself be part of another assembly. When the manufacture of an assembly always involves a certain amount of scrap, the material and activity consumption must be increased by the system so that the required lot size is output. The assembly scrap in the production version is used in material requirements planning in the DI system, in APO, and in product costing to calculate the input quantity from the quantity to be manufactured. The secondary requirements are determined for this input quantity.
Caution
Note, that the variance calculation cannot take planned activity scrap into account.
Integration
Be aware of the following differences between the assembly scrap specified in the material master/product master and the assembly scrap specified in the production version:
Assembly scrap in material master/product master (not relevant in this scenario) |
For assembly scrap in iPPE: Assembly scrap in the production version |
|---|---|
Valid for a material |
Valid only for the special production version |
The assembly scrap in the material master is based on the lot size . The assembly scrap in the product master is based on the input quantity . |
Based on the input quantity . |
Not appropriate for materials manufactured with iPPE. |
Used for materials manufactured with iPPE. |
The assembly scrap in iPPE is entered in the iPPE access object as a percentage of the input quantity. This means that this assembly scrap automatically increases the input quantity when the iPPE quantity structure is exploded. As a result, the assembly scrap is automatically taken into account both in material requirements planning and in product costing.
In costing, the planned scrap percentage of the component quantity is calculated automatically when the iPPEquantity structure is exploded. The explosion can be performed with or without rounding.
From the APO confirmation, the system determines the planned scrap percentage of the target component quantity at the time of the goods receipt. When the goods receipt is entered, the confirmation determines which components were used and calculates the percentage of planned scrap per component.
Example
Suppose you are manufacturing 90 circuit boards. 10% assembly scrap always incurs during the production process. You have specified this as the assembly scrap in the production version. When you produce the boards, the system increases the material and activity consumption so that the required 90 boards are produced.
When you manufacture the boards, material requirements planning increases the requirement to 100. This also increases the requirement for the input components. That is, the consumption of materials and activities for the subordinate components is increased as if it were intended to cost or produce 100 boards. The system costs the 90 boards on the basis of a quantity of 100 and calculates a scrap quantity of 10 boards for the three subordinate components. In addition, the activity consumption at the two operations is increased by 10% to 100 hours.