Can you compare SSRD and time series designs?

I am happy to share. =D

Thank you.

•Very similar in construction and logic to the time series designs but SSRDs uses A and B notation instead of O and X.
•The time series designs tend to be used when an evaluation involves large-scale policies, whereas SSRD tends to be used when an evaluation is conducted for an individual
•SSRD has a long History in Social Work
•For SSRD, despite practical obstacles, it was popular because it is relatively easy.