HI Swathi,
Basically, ETO is a Complex situation where even the product design is finalized after reeving the Customer Order.
Normally the Business Process Starts like this
1) Entry, Quotation : This is one of the biggest step to start the business, since i have seen a client who is having a setup meeting with client to explain the product & its deliverable. Since its a unique product the cost & time would be high. In this discussion business already have a Project Design ( Previous Project) & based on the time,cost & deliverable will be decided once the Customer agree the same.
2) Production Planning Team : After agreement the sales team send a information to the Production Team to make a schedule as per as client time liens In this time A project will be created with the Sale Order. Sales Order will have account assignment category of the WEBS for every line item level
3) Project Executing : Project team wlll execute the Project & delivery the same to the Customer
4) Billing : Based on the Agreement with the Customer invoice will be raised.
more or less the same process would be in place in ETO.
From the Point Of the SAP :
1) ETO : Here the Sales Order would be a Cost Object means all the revenue & cost would be booked at the Sales Order Level.
2) Requirement Type - Requirement Class - Special Stock : these are the 3 setting important to make a Costing for the Project.
3) Delivery Billing : After completion of the it would be transferred from the Project Stock to Sales Stock & the same would be delivered and followed by billing.
Coming to your point : what is the difference between the Sales process with or without Project.
Cost Object : Normal Process the Sales Order will not be a Cost Object but in ETO the Sales Order would be a Cost Object
Account Assignment : Account assignment would not be there in normal sales process
Stock : Normally stock would be a Plant Stock, but in this case it would be a Proejct or Sales Order Sock.
Billing & Delivery : WBS element would be there as a Account Assignment in FI Journal Entries in case of ETO & Normal process WBS would not be there as Account Assignment in FI.
Please find the below screen :
Regards
Raj