Calculation of Activity Scrap  

Use

For a product produced in-house, you can specify in the production process model (PPM) exactly how much scrap is produced in every processing step. If scrap is produced in an activity, the activity has to process a larger quantity in order to achieve the required yield. The activity therefore consumes more components. In the case of quantity-dependent processing times and quantity-dependent resource consumption, the net duration and the resource consumption of the activity is also increased. The system corrects the quantity during the PPM explosion. The total quantity to be produced of an activity is calculated during the PPM explosion according to the following formula:

 

Total Quantity = Yield x 100% / (100% - Scrap in %)

 

In the PPM, you can choose whether the yield to be produced of an activity is:

The total quantity of the activity is calculated based on the order quantity.

When a successor activity has to process a particular total quantity, this yield has to be delivered by the predecessor activity. The quantity of the predecessor activity is therefore also increased to allow for scrap in the successor activity.

Prerequisites

You define scrap either at assembly level or at activity level for a product, otherwise too much scrap is calculated.

 

Example

Scrap Without Material Flow

An order comprises three successive operations that each consist of one processing activity. You have not set the Material flow indicator for the relationships between activity 1 and activity 2, and between activity 2 and activity 3. This means that the activity quantities are to be calculated individually for each activity based on the order quantity. You have entered the following scrap data for the activities:

The quantity to be produced by the order is 100 pieces. Using this data, the system calculates the quantities to be processed or that are required in the activities:

If each of the activities require special components, these have to be provided according to the activity quantities, for example, 105 pieces for activity 1, 108 pieces for activity 2 and 106 pieces for activity 3.

 

Scrap With Material Flow

As in the example above, an order comprises three successive operations that each consist of one processing activity. You have set the Material flow indicator for the relationships between activity 1 and activity 2, and between activity 2 and activity 3. This means that the quantity to be processed in an activity is to be provided by the predecessor activity. You have maintained the following scrap data in the PPM:

The quantity to be produced by the order is 100 pieces. Using this data, the system calculates the activity quantities:

For the order to deliver 100 pieces, the first activity must process 120 pieces, the second 114 pieces and the third 106 pieces. The components have to be provided according to the activity quantities, for example, 120 pieces for activity 1, 114 pieces for activity 2 and 106 pieces for activity 3.