Is it correct - Project Approval with Revenue Budget-warranty period

Good Morning

We are using R12.1.3

After  creating the project - project is getting  approved by way of workflow approval.

Here the question asked by one of project manager also one of  the approval members.

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At the time of project is sending for approval - Project No, customer , Description only available.

But the project manager says  - without  know the project budget  revenue value -

can we  enter budget value before  sending for approval.

Also  can you please share the steps to create the project - is there any way we can give  warranty period after project is completed.