do u know about configuration management tool, what is the purpose of maintaining all the documents in configuration management tool?

It is focused primarily on maintaining the file changes in the history.
Documents are subjected to change for ex: consider the Test case document.
Initially you draft the Test cases document and place it in Version control tool (Visual Source Safe for ex).Then you send it for Peer Review .They will provide some comments and that document will be saved in VSS again.Similar the document undergoes changes and all the changes history will be maintained in Version control.
It helps in referring to the previous version of a document.
Also one person can work on a document (by checking out) at a time.
Also it keeps track that has done the changes, time and date.
Generally all the Test Plan, Test cases, Automation design docs are placed in VSS.
Proper access rights needs to be given so that the documents don’t get deleted or modified.