Values are the qualities we believe we should optimise for in order to meet the Needs. They can be used as measuring sticks when deciding how to apply Principles, or which path forward to take (eg. will X change give us more predictability or less?).
At a system level, if you have these things you are most likely to meet the Need. Secondly, at a personal level, these are the things that will keep me in the system because they will ensure that I meet my Needs.
For some examples of Values, see the Values Catalogue.