My chapter never used a point system. I don't know if any of the other chapters on campus did,
I don't remember anyone ever talking about them or anything.
We had mandatory events (like Initiation, Rush, Philanthropy, Meetings, etc.) If you didn't show, you got fined. (It was failry inexpensive, like $5 usually). You could have an excuse, but you had to turn in a written one in advance. (Of course, if there was an emergency (a
real one), that was an exception). You were only given a certain number of excuses per semester (I think 2 or 3 but not positive).
Another thing, we had to complete individual service projects, but the chapter does a lot of things that count. For example, we usher all of the events at the school's Conservatory of Music. So each member has to usher X times a semester (it varies depending on the number of performances & the number of members). If you usher more than the required amount, that would count towards individual service projects.
Anyways, before this gets to long... we created a status called Semi-Active Member. So if you know you have a really heavy courseload, or you're student teaching or whatever you can still participate, but you have fewer requirements (the number of different events is reduced). You still pay dues & are welcome at all events.
In fact we never prevented anyone from attending social events. Even if you were inactive, you were always welcome.