Queries about PS module and subsequent integration with MM, SD and PP

Question

Hello Experts,
Am posting the query for the first time so hope you all will excuse if something is not correct. Here is a scenario that I am working on:
- The customer is a project engineering company wanting to use PS (but without networks - ONLY WBS)
- We copy the neutral material BOM to create a project BOM
- We create a multi-item sales order with a/c assignment to different assembly groups from the project structure for deliveries and billing
- Project COST planning (V002 and V000) is carried out
- Material stock must be valuated
Following are the scenarios for commitment and actual costs:
1. Direct procurement:
Process: Material purchased with a PR generated from SO item --> PO --> GR --> IR
Query: I am guessing that commitment will be generated through PO creation for WBS. What about actual? What type of cost element should be assigned to the G/L being affected during GR so that I can get some actual against the WBS?
2. Procure to produce:
Process:
Common Purchase: Material purchased through a normal PO (without a/c assignment to WBS) for common unrestricted stock.
Project purchase: Material purchased through project PO (with a/c assignment to WBS - resulting in commitment generation) and special project stock at the time of GR
Both materials (from common and project PO) shall be used for production of an assembly which is being produced using a production order which is assigned to the WBS element.
Query:
How and when would I be getting the commitment / actual effects here?
- Is any commitment generated when I create a production order?
- Is any actual cost posted when I issue raw material to this production order?
- What if the raw material being issued to production order was not purchased using this WBS? Is the actual cost still loaded on this WBS?
- What happens when I confirm the production order to generate FG stock?
What should I be careful about when defining this scenario and what type of cost elements should I be using?
3. Procure - Produce - Sale
Process: In certain cases, material procured  for common stock is issued for project production,
Material produced for one WBS/Project gets issued for another.
Query: How does SAP react in this case about the entire commitments and actual cost postings?
I know there are too many queries but I hope you all understand that it is a project-engineering-manufacturing company so on one side the commitment-actual costs are important to be assigned to right project-WBS. At the same time, they also want to have the flexibility in their production activities.
Awaiting eagerly for all possible help.

Answer 1

Link farming is not allowed on this forum. Hence, i would not be able to post any links here. Just to get you started type "SAP Help" in Google. Open the 1st link and under Frequently used click on "ERP Central Components". Then under SAP ERP Central Component 6.0 click on "English". This will take you to a new window. Here, again click on "SAP ERP Central Component". Then click on Logistics - Project System.
You can find all the relevant topics listed here. Go through each one of them and revert with specific queries.