The cash flow of a position may contain many derived business transactions. When the position is changed or the cash flow is recalculated, the system might recalculate all the derived flows, which will take a long runtimes, even cause something wrong.
You can set the derive transaction update Period in T-code SPRO under path:
Treasury and Risk Management -> Transaction Manager -> General Setting -> Accounting -> Assign Accounting codes and Valuation Area
Period for derived business transaction is generated automatically for a position and is to be updated on the database. To determine a standard end date for all positions, the period is added to the year of the period.
In case the setting is maintained, in some special cases might be required to generate the derived business transactions for the whole cash flow of the position.
In order to achieve the option Ignore update period rule is available in the transactions TPM19 and TPM27.