Executing Cost Center Summarization
1. Create a representative
cost center for every node of the cost center group you wish to summarize, if these do not yet exist (see:
Representative Cost Centers).2. In cost center group maintenance or in the standard hierarchy, enter the representative cost center in the reporting information. To do so, choose Master data
® Cost center group ® Create or Change in the cost center group menu. Choose Extras ® Report Information in the structure screen then enter the summarization cost center in the Report information dialog box under Repres. cost center. 
Report information maintenance does not verify whether the cost center exists in the
controlling area or not.3. For each hierarchy you define a summarization. When doing so, you must determine the highest group node and the criteria according to which the cost center transaction data is summarized:
a) Cost center group
You always create the summarization for the highest node of a cost center group.
b) Further settings
You determine whether to:
i) Summarize costs,
ii) Process quantities and/or whether sender cost centers are summarized in stages
iii) Delete the data from the summarization cost center completely, or whether to reset it by period.
You maintain summarization in the Implementation Guide (IMG). For more information, see the IMG for the Cost Center Accounting component (CO-OM-CCA) under Information System
® Maintaining Summarization. 
You can also choose Extras
Choose Check to determine whether the R/3 System created and saved the summarization correctly for the period in question.
4. You carry out summarization in the Cost Center Accounting component. Choose Information system
® Tools ® Summarization and enter the summarization.Summarization applies to a cost center group for given periods within a fiscal year.
You can start summarization online or in a background job.