Knowledge Management

Question:
Hi! I understand that when doing materials planning in Project System (for network/activity), we can choose to create reservation & purchase requisition when assigning the item category 'L' (non-stock).
My questions are:
1. Is the PReq created automatically at the same time when the reservation is created?
2. Is the PReq for stock or for direct consumption to the network/activity?
3. I guess 1 & 2 will then help me understand better how different is this scenario compared to creating only a reservation and getting MRP to generate a PReq followed by a PO to bring item to stock before issuing out to the project using the reservation number.
Reasons for the above is I am trying to decide what process is best for the users. In their case, the request for material is always from a dummy plant with zero stock (there are some valid reasons here which I will not illustrate). This is so that a stock transport order is created to bring stock from a supplying plant to this dummy plant for further issual to the network/activity.
So in the project, item category 'L' is always used to generate a reservation for such requests/planning. I am thinking that the user can either run reservation list to monitor and manage the issual of goods from there by creating the STO separately, OR schedule MRP run to always create a purchase requisition so that creation of STOcan be handled via ME57 (assign & process). One side question here is whether MRP can create separate PReqs if more than 1 reservations is created for the same material as we want to manage the requirement individually? The only reason why I consider using MRP is a common process of using a single transaction ME57 to manage this type of requests for STO and procurement from external parties.
Now, I read in SAP Help Documentation that we can also create a reservation and a PReq. However, I am not familiar with this process and hence the query here.
I hope I am not confusing anyone with my many queries here. Because I have so many options here and I am not experience in the MRP area, I am in a dilemma as to what option to choose.
Would appreciate any advice on the above.
Cheers!
Doremon
Answer:
As in any WO system within SAP the components that are designated as item cat. "L" are for stock items that will generate a reservation against the stock of the plant.
Whether or not there is any stock available or not, in that this sets up the requirement against the material and then the Requisition/planned Order would be created based on the MRP run.
If you are interested in purchasing this material directly to the project then this item cat. should be set to "N" for non-stock. This will create a Preq directly and the account assignment for the Preq. would be your project. This will bypass the inventory and not show as consumption to the particular material.
Hope this helps