Maturity is not about the practices you follow, the guidelines you adhere to or how seldom you have things go wrong!
Maturity is about how you manage your protection and sustainment activities for the assets which support your vital services. It's not about do you do "it", its about how you do it.
Is it a Defined process?
Is it a Measured process?
Is it a Managed process?
or is it simply done? Is it a "they always figure it out, we get it done" process?