Can anyone please tell what is change request management tool and what is involved when a change request is submitted to this tool?
A change request management tool is for users to request changes in the software.
When the software development process begins, there is an agreement between the development team and the users (or their department) about what the software will do. This is called the requirements. Once everybody agrees on the requirements, preferably in writing, development begins.
If the users discover that they need to change the requirements at any point during development, they make a change request. Those requests are logged into the change request management tool. The development team reviews the request and negotiates with the users over the change -- how much additional time or money it will take -- until they reach an agreement.
Once the software has been deployed, there may be additional changes identified by the users. They record their requests in the change request management tool. Periodically, the development team reviews the new change requests and makes an agreement with the users about which of those requests will be included in the next release of the software.
Using the change request management tool help to manage "scope creep". It helps both sides to assess the additional work needed on the software, and keeps the whole process organized.
If done correctly, there will be a record of the changes requested, the changes made, and the changes currently in process. Software improvements will be prioritized.