The program reorganizes the stock requirements list. I really don’t know how it works but do know that it cleans up items that appear in the stock requirements list that should not be there (e.g. planned orders that have been deleted, deliveries that have been processed but still appear, etc). I recall running this program as far back at release 2.2 so it’s been around a long time. I’ve been at two customers that have set it up as a batch job to run weekly just to clean things up. I never got a good explanation as to why the stock requirments list got messed up in the first place but do know that this fixed the problem.
I have no idea why it runs long when you specify * for the material and a plant. What happens if you leave the material field blank and just run it for a plant, does it still take a long time? It seems to me that blank in the material field is the same as * so I don’t understand why you would run it that way.
Hope this helps