What makes a good school-wide support system?

I've been heavily involved with a new, mandatory after-school program for students with missing assignments.  We call it our After School Assistance program, ASAP.  I think our councilor found that name someplace.  It's kind of like a detention, but instead of getting one for behavioral problems, students get one when they have less than a C- and are missing assignments.  We've been running it twice a week for three weeks now.

[Quick standards-based grading justification of this policy: Obviously, in a traditional grading system, 0's on a homework assignment can kill a student's grade faster than anything.  But if you're in an 80-100% standards-based grade system, missing assignments aren't that big a deal to the grade, so why have a special intervention program just to solve that problem?  My thinking, as an advocate of both ASAP and standards-based grading, is that, in a SBG system, you need a certain level of proficiency to pass the assessment.  The homework, whether it's graded or not, is meant to help you do that.  If you ace all the assessments, you obviously don't need the practice for proficiency.  If you don't, then the homework's extra practice might be just what you need to help you get the standard.]

We started the program before we had all of the logistics worked out, and part of that was because I really wanted to get it started.  Teachers complain about homework assignments all the time.  So even without all the lines of communication being operational, we started pulling students in after school.  For the first few weeks, teachers asked me, "How do we do X?"  My answer was usually, "I don't know.  Let's tell the student and the student's parent that she has to come, and we'll work it out from there."  With a couple of notable failures, that seems to work out.  It's gotten me to thinking about how I would assess this program's achievement so far, and that leads me to ask, what makes a good school-wide learning support system?

So, spitballing: A new program should address a need the school has.  It should not take the place of something a teacher should be doing.  It should not get in a teacher's way, or place an undue burden on the teacher.  It should remove a concern that a teacher has about a small minority of her students, so that she can focus on better instruction for all students--it should deal with small numbers of students with similar learning challenges.  It should not enable the systemic marginalization of a minority student population--it shouldn't keep the tough cases out of sight and out of mind.  It should SOLVE the problem, not just change the problem or make it look like something else or allow the school to say they have a program in place--it shouldn't be window dressing.  Like all things in school, it should have learning as its goal.  Like all things in school, it should be student-directed.  Like all things in school, it should be data-informed.  (I've decided I reject the phrase "data-driven.")  It should help answer one of the key questions: What do you want students to know and be able to do?  (Curriculum.)  How are you going to give it to the students?  (Instruction.)  How are you going to tell when students get it?  (Assessment.)  What are you going to do with the ones who don't get it, and what are you going to do with the ones who do?  (Differentiation; interventions and enrichments.) 

I feel like this program is still in its infancy, as is my capacity to evaluate it.  But I think it still scores pretty well: It definitely addresses a need of our school, and I definitely have the data to show why we need it.  I think teachers get great benefits for the time they put into it: they fill out a form and agree to give students 50% credit for late work, and in exchange they don't have to chase students for work they need to get done.  Students who need extra practice or time or structure get it; students who don't, don't have to sit through it.  We have, I'm guessing, about an 80% success rate: with very few exceptions, students who come to ASAP finish their work that day.  I don't know how many multiple-offenders we have, but my impression is that it's a relatively small number.  In all, it seems like a good school-wide support system.  There are improvements to be made, but it seems like a good start.

Readers, what do you think?  When schools create programs to help teachers do their jobs better, how do you know they're working?