Setting Timeouts 
On the Timeout tab, you can define timeouts for the precalculations in the various workbooks. This allows you to prevent the precalculation server getting stuck when processing a particularly large workbook.
Before defining a timeout value, you can view the workbook in BEx Analyzer. To do this, select the workbook from the list and choose Start Workbook.
To set a timeout, switch to change mode (the Toggle Between Change and Display Mode icon).
Enter the required value in minutes in the Timeouts column.
If you want to swap a workbook in the list with another one, select the workbook in the list and use F4 help in the Title of the Workbook field.
Select another workbook (using Search if required) and choose Select Entry.
If you do not define a timeout, there will be no timeout for this workbook.
If you enter a value in the Timeouts column and leave the Title of the Workbook and Workbook ID columns blank, the timeout value applies as the standard setting for all workbooks that do not have their own timeout values. If you subsequently set a timeout value for one of these workbooks, this value overwrites the standard setting. Timeout value 0 means no timeout.
Example
Enter 10 as the standard value (without entering a workbook ID). Workbook 1 is assigned the value 20, while workbook 2 is assigned the value 0. For workbook 1, the timeout is 20 minutes, while there is no timeout for workbook 2, and the timeout for all other workbooks is 10 minutes.
For more information, see SAP Note 1371345.