Valued systems regularly used in these times (8)
I believe the answer is:
assessed
'valued' is the definition.
('assess' can be a synonym of 'value')
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for assessed that I've seen before include "Evaluated" , "reviewed" , "Estimated" , "checked out?" , "Appraised" .)