throug Easy cost planning process in proj systems ,i want to do sales cycle
i am new to proj systems module
i am trying to create 1 PS :quotation --> PS: Order
> PS Billing Request
>F2 Billing through Easy cost plannng methodology.
i also created till 1 PS :quotation --> PS: Order --> PS Billing Request without Material
while entering a WBS in quotation --> PS: Order --> PS Billing Request ** randomly from F4 options then system is picking but after saving , the selected WBS is not displaying.
at the creation of F2 invoicing , system is throwing an error as "Document 70000074 does not contain any items with open quantities"
Pls guide me in a better way even i dont know the full funda of Easy cost planning .
regds