Changed Sequence of Effectivity Periods
A date shift redefines the valid-from date. Valid-to dates are recalculated by the system.
This can change the sequence of effectivity periods for a change object (such as a characteristic or the characteristics of a class). This produces a negative effectivity: The valid-to date is before the valid-from date. Two effectivity periods overlap. In this overlap period, different versions with different change numbers exist (see the following example for a BOM item).
In this case, you cannot perform the date shift. The system creates a temporary log listing all the change objects that prevent a date shift. (see:
Special Features of Object Types).Exceptions
For the following objects, you can still perform a date shift despite a change in the sequence of effectivity periods:
If the date shift results in a change to the sequence of effectivity periods, you usually see a warning message. You can then check the BOMs and routings affected. You can perform the function as soon as you confirm the warning message.
In Customizing for Engineering Change Management, under Set up control data, you can use the Error messages only indicator in the Date shift dataset to specify that warning messages are always converted to error messages in these processing situations. This means that as soon as you perform a date shift that changes the sequence of effectivity periods of a BOM or task list, an error message appears and you cannot perform the date shift.