You only need a source structure for costing co-products if you want to distribute the costs to the co-products using cost elements.
If you don't want to distribute the costs using cost elements, the costs will be distributed on the basis of the apportionment structure in the material master record. In this case you do not have to process this step.
In this IMG activity, you define the source structures used when settling and costing joint products.
A source structure contains several source assignments, each of which contains the individual cost elements or cost element intervals to be settled using the same distribution rules.
In the settlement rule for the sender you can define one distribution rule, in which you specify the distribution and receivers for the costs for each source assignment.
The object in question has incurred both direct and overhead costs. The direct costs are to be divided 50% each between a fixed asset and a cost center, while the overhead is to be settled in full to an administration cost center in CO.
To do this, you would create a source structure with two source assignments:
Check whether you need to use source structures in your settlement procedures. If you are settling to cost elements, you do not need a source structure. Otherwise, create a source structure as follows:
The quantity structure of the material is determined by means of entries in the material master record. If none of these entries exists, the quantity structure is determined by means of the quantity structure determinaton ID specified in the costing variant.
For more information on costing co-products (such as quantity structure determination), see the document CO - Product Cost Planning in the R/3 Library.