Process in manufacturing industry without PP, using only PS

Here i am discussing a scenario which i have faced, In a manufacturing unit management decided to use only PS for their Process (All Costing like Machine, Man, Material, third party etc.). We have implemented the Assembly Processing in that organization but manufacturing without PP Module.

Please check the scenario described as below: 
1. Enquiry from customer
2. Quotation creation
3. Sales Order creation
4. Automatic Project creation along with sales order
5. Budget allocation for that project
6. BOM creation 
7. Finished material to be assigned to project activity with -ve value
8. BOM transfer 
9. purchasing of the component of BOM
10. Check all the materials to be present in Project Stock
11. Confirmation of that activity which will consume all component and stock posted for finished good assigned with -ve value.
12. all the machine and labour are booked via internal activity usng work center and activity type
13. create delivery for that sales order using material present in project Stock.
14. and accounting will be done.
and settlement according to client.

thanks
Sunil