In what ways can finance, help the supply management group purchase products and services at a lower cost?

In what ways can finance, help the supply management group purchase products and services at a lower cost?
The finance team is supposed to be focused on cutting costs, and raising the bottom line. While there are many ongoing accounts that the finance team needs to be aware of, one concern of theirs is how to acquire their goods needed, at a lower cost. In other words, their goal is to lower the COGS (cost of goods sold).