Target Update

Hello every body

Any one have Idea about using target update command in p3.

1-when to be used?before project start or during project execution or both?
2-what are the limitaions in using target update both technically and contractualy?
3-what are the possiblites of updating a target?
is it applicable for updating all the data as when we are going to creat new project?

do u advice by using target update?

thanks in advance by your answers.

Ali
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