Using Solver for Schedule

I'm lost on this problem. I have a worksheet where I have 8 teachers that need to be scheduled as advisors during the week. The target cell (Total Difference) has to be 0 in that the difference between the number scheduled and the number available each day have to be equal with no shortfalls. Several of them can't work on certain days, 1 if they can, 0 if they can't, with all teachers needed to be available at least 2 but no more than 3 days per week. The cells in the total days column have sum functions already in them - that's the part that has to be at least 2 but not more than 3. The Faculty Scheduled and Difference rows are also sum functions. Since the numbers have to be 1 or 0, I thought I could make them binary, but that doesn't seem to work. I've tried making the variable cells have a constraint of <=1, indicating that they can be scheduled that day or not, but that doesn't work or I'm still doing something wrong. If I try to make the total days range >=2 and <=3, every cell in the total column ends up being 2, even if it had zeros straight across the days row. Several times when I ran Solver, it scheduled Teachers A and B for every day, put 2 in the total days column and then everything else stayed 0. I'm completely without a clue.

Faculty Mon Tues Wed Thurs Fri Total
Days
Teacher A 0 0 0 0 0 0
Teacher B 0 0 0 0 0 0
Teacher C 0 0 0 0 0 0
Teacher D 0 0 0 0 0 0
Teacher E 0 0 0 0 0 0
Teacher F 0 0 0 0 0 0
Teacher G 0 0 0 0 0 0
Teacher H 0 0 0 0 0 0


Faculty
Scheduled 0 0 0 0 0 0
Faculty
Needed 5 4 3 4 5 0

Difference -5 -4 -3 -4 -5 0
Total
Difference -21

Based on your info I've set up a model for you.

Alf

Thank you so much! Your constraints were so simple, I had 30 at one point! I wasn't sure if I should put a 1 for days they could work directly in the cell or not. Plus I didn't have separate cells showing the min/max days they could work, I didn't even think of that. I spent hours trying to figure this out, and with your help I finished it in five minutes. I can't thank you enough!

You arewelcome and thanks for feed back.

If this solves you problem don't forget to mark this thread "Solved"

Alf

Ps

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