When students are forced to go to ASI, they automatically get a way to get a better grade on the assignment they didn't complete. Instead, students should get a zero on their assignment so their grade will be effected. This way, students will have a reason to do the assignment. Why would a student want to start doing their homework when they can do it later at ASI?
Also, some people have multiple after school activities that they can't miss for a random ASI for forgetting to complete one minor worksheet. Legitimate after school activities are more important than an ASI for a random worksheet.
A solution is that you shouldn't get an opportunity to redo the assignment. The punishment will be inside their grades.