If you are running a purchasing department then you have a job of managing purchase costs and keeping employees supplied with products they need to see or do their jobs. So you could use purchase requisition to allow employees to request products and the request for quote to see if you can source product for a better price or other conditions.
This works on the requisition being in review state. You can leverage the workflow and have a step to review if items should be sent to RFQ based on conditions in the workflow.
Here is a quick overview.
AX2012 R3 CU11