In Item Master Data > Planning Data tab you can define Tolerance days.
Related to order scheduling: If there is negative stock in the time line, the item will be shown as shortage in MRP. Here you can enter the number of days. Negative balance is tolerated.
Example:
Stock = 0
Sales order = 3rd May
Purchase order delivery date = 6th May
Material comes 3 days late
If the tolerance date for this item is defined with 3 days or more, the result is: OK
If the tolerance date is < 2, MRP must display this piece of information.
In MRP the filter "Only shortage" means:
Display all entries which have a negative balance in the timeline.
(MRP Filter - Predefined Filter)
In this example the item has a balance of 0, but a negative balance between 3rd and 6th May
MRP displays this item if the item has "tolerance days" < 3 days.
MRP does not display this item if the item has a "tolerance days" > 3 days.
Negative Balance in past
Negative Balance in the past is ignored entirely.
The calculation for the time area starts from the current Date.
Example:
Today is 5th May
Sales Order is 3rd May
Delivery = 6th May
The system calculates: Balance is negative from 5th – 6th May = 1 day.