Evaluating Vendors in the Background 
You can evaluate your vendors on a regular basis by means of background processing. The Evaluation in the Background function can be found in the Purchasing menu.
Prerequisites
If you want to start a background processing request for vendor evaluation, you need a variant (to limit the number of vendors to be evaluated, for example).
Maintaining and Displaying Variants
When you invoke the Evaluation in the Background function, you can display existing variants in editing mode of the step list, and create new variants or change existing ones.
To do so, choose Edit
® Steps and thenProcedure

You require certain authorizations in order to carry out evaluations in the background and define new variants. If you have any queries in this connection, please consult your system administrator.
If you require more detailed information about working with background processing requests, please refer to the documentation
Subsequent Maintenance of Background Evaluations
In background processing, you usually evaluate vendors belonging to the same group (that is, vendors who have the same weighting key). However, it is possible that you have selected an interval that contains different groups of vendors. For this reason, you have not entered a weighting key.
To ensure that the scores are calculated correctly, you must therefore subsequently maintain the weighting key for such evaluation records at certain intervals of time.
The evaluation records in question can be determined using the analysis report Vendors Without Weighting Keys.
This function can be found in the purchasing menu under Master data
® Vendor Evaluation ® Follow-on functions ® Vendors without weighting keyFrom this report you can branch directly into the screens for maintaining evaluations.