Characteristic Compounding with Source System ID
If there are identical characteristic values describing different objects for the same characteristic in various source systems, you have to convert the values in such a way in SAP NetWeaver BW so as to make them unique.
For example, the same customer number may describe different customers in different source systems.
You can carry out conversion in the transfer rules for this source system or in the transfer routine for the characteristic.
If work involved in conversion is too great, you can compound the characteristic to the InfoObject Source System ID (0SOURSYSTEM). This means it is automatically filled with master data. The source system ID is a 2-character identifier for a source system or a group of source systems in BW. The source system ID is updated with the ID of the source systems that provides the data. Assigning the same ID to more than one source system creates a group of source systems. The master data is unique within each group of source systems.
You already have 10 source systems within which the master data is unique. Five new source systems are now added, resulting in overlapping. You can now assign the 10 existing source systems to ID 'OL' (with text 'Old Systems') and the 5 new system to ID 'NE' (Text: 'New Systems'). Note: You now need to reload the data.
If you use characteristic Source System ID, you have to assign an ID to each source system.
If you did not assign an ID to each source system, an error will occur when you load master data for the characteristics that use the Source System ID as attribute or in the compounding. This is because, in data transfers, the source system to source system ID assignment is used to determine which value is updated for the characteristic Source System ID.
Master Data that is Local in the Source System (or Group of Source Systems)
If you have master data that is only unique locally for the source system in SAP NetWeaver BW, you can compound the relevant characteristics to the Source System ID characteristic. In this way, you can separate identical characteristic values that refer to different objects in different systems.
Data transfers from one BW system into another BW system are an exception, that is, where this 1:1 assignment does not apply. See also the Exception Scenario: Data Mart section in Assigning a Source System to a Source System ID..
RRI (Report-Report-Interface) and Drag & Relate
Characteristics to be traced in your original system using the RRI (Report-Report-Interface) or Drag & Relate should have characteristic 0SOURSYSTEM as their attribute. Otherwise problems might occur during the system copy.
When you integrate your BW system into SAP Enterprise Portal, the Source system characteristic is used to define the logical system of the business objects corresponding to the characteristic values. In this system then, functions specified using Drag& Relate are called (for example the detail display of an order or a cost center). Every Business Content characteristic that corresponds to a business object has characteristic Source System as its attribute.
If you assign more than one source system to a source system ID, you can define one system of this group as default system. This system is then used in the Report-Report-Interface and in Drag & Relate for the return jump. This default system is only used if the origin of the data was not yet uniquely defined by characteristic 0LOGSYS.
Deleting and Removing a Source System ID
You can only delete the assignment to a source system ID if it is no longer used in the master or transaction data. Use the Release IDs that are not in use function here.