Hi Habib,

All three of these questions touch upon some core "PMI"-isms that should definitely be understood:
1) A project isn't done until the Closing processes are complete, i.e. just because the final deliverable has been accepted, doesn't mean your job as a project manager is done!
2) You can't inspect in quality, i.e. address quality concerns before inspection! (the earlier the better)

Knowing these two concepts will help you answer your questions.

1-Project got its final prodcut verified and accepted and PM will be leaving for 2 weeks and team want to celebrate sucess ...what he has to do before leaving?
- take team to lauch for celebration OR
-Start project closing process??
2- As an offer to reduce the cost of many defacts ...in which you have to invest

Testing or inspection??

3-acceptance of IT product was accepted without code verification...this is will most likely be aproblem of which phase/stage?/
warranty or inspection stage??

thanks,