website states that 20cu per sem is very heavy load though...
http://www.suss.edu.sg/resources/FAQs/PT/Pages/Programme-Structure.aspx
What is the typical study load of a Singapore University of Social Sciences undergraduate student?
You may take a minimum of 5 cu and a maximum of 20 cu of courses per semester (excluding UCore courses).
You should note that 20 cu of courses in a semester is a very heavy study load.
20cu is definitely heavy but it doesn't mean it's not possible. I'm currently working full time and have been taking 20cu for the past 4 semesters. This is what I've done for the past semesters:
Jan 2017 - 25cu (4 core modules + 2 2.5cu UCores)
Jul 2017 - 25cu (4 core modules + 1 5cu UCore)
Jan 2018 - 20cu (4 core modules)
Jul 2018 - 20cu (4 core modules)
I'm not the only one taking the full load while working full time.
so ultimately it depends on how much time you have, how much of this time are you willing to use for the program, and of course, how well you want to do.