BeckysTXS
I think the solution to the confusion you outlined in your 1st post is the use of linear programming. You site numerous constraints which can be used in the equations to find that single point date!
Unfortunately it has been a very long time ago I used it in my mba class and never used after that! All that effort amounted to zilch, nada, zip, gone!
Hence, I can no longer provide any esteem guidance to the cause!