nope that's not possible because every x is independent of the other one. And
the x's are not the same. Maybe this illustration of the problem as a whole
will help.

I have to assign people for treatment in a month (people from type 1 --
x1..x4, people from type 2 -- x5...x8) So x1 is type 1 in month 1 and x2 is
type 1 in month 2. But the costs of type 1 people are the same in every month.

I need to give an answer to what the ammount of treatable people per month
is, so x1...x8 are my decision variables. Another question is then that how
much 16 is allowed to change when the optimal solution still remains the
same. But as the sensivity report adressess all the 16 as independent
variables this is a question hard to answer for me