Does calculate lead times and Roll up cumulative lead times run in incremental basis?

Summary:

We ran this ESS process for a range of items 1st time after conversion and it ran for 10+ hours. We want to know if we run tomorrow with calculation date = Tomorrow + 1 day, does this run only for assemblies which routings have been either newly created or updated since last run when it is run for same range of items, or does it again for all the items in item range?

Content (required):

Which is the logic of picking routings for this roll up program? Does it run for all items in range or is it intelligent enough the find incremental routing- new or changed and run it only for them? Point is what is the logic of picking the routings for this program run?