Lawson S3 IC12 Average Leadtime

I believe setting the leadtime control to R is the same as S but it allows you to review the leadtime for those IC12 records using IC226

Leadtime Review Report (IC226)

Run Leadtime Review Report (IC226) to print a report that lets you review
and adjust the number of leadtime days required for inventory items.
You can limit the items listed on this report by location, report group,
buyer code, and/or inventory class. This program sorts items by location and
buyer code. This report lists the item's primary vendor, previous, last,
current
average, and new average leadtime days.

IMPORTANT This report only lists items when the leadtime
control flag is set to Review defined in the IC12.1 (Item Location) Source
form. You can set this flag manually for reporting reasons. Otherwise, the
Inventory Control application sets this field if the new average leadtime
is 50 percent different from the previous average leadtime. A new average
leadtime is calculated each time a purchase order is received for an item
in the Purchase Order application.

The flag switches to R if the last lead time is way off the past few average lead times (calculated when set to S).
It’s a warning that something wasn’t quite right about the last delivery and that you should review why. You need to set it back to S after reviewing and setting the average lead time back to a normal value.

I wasn't aware of this. Good to know!

Thank you all for the information, I really appreciate.