In a large organization, how do you typically request permission to perform a network change?

Network change in larger organization follows hierarchy of approval.

Hierarchy of approval will start from the lowest department. The lowest department must prepare a written proposal, stating that there is a need for the network upgrade. Attachments such as proposed price list for the new equipments to buy also comes up with the proposal. Once that all documents are prepared, signatures from approval departments must be gathered. Each signature should be present and complete.