A little problem to be solved using integer variables (in excel or aimms);
Suppose we have 5 forest stands, with the volumes given as below:
The distances to our basis in A or B are given below (these are random numbers).
A and B both need at least 30.000 tons.
Suppose also when you harvest a stand, it’s completely to one of the destinies, A or B – it can’t be fractioned.
I want to minimize distances, subject to the constraints.
What’s the solution of this case?
The data is given below:
The decision variable is reserved in columns K and L.
The sumproduct per destiny must be greater than 30.000.
The distance is calculated multiplying vol*distance*decision variable
The objective function is the sum of distance*decision variable.
In solver, we include the constraints. And we want to minimize distances.
Because this test is very basic, there’s not much possibilities. In general, integer programming is difficult.
Other little detail: if we need necessary to harvest the plantation, the sum of the decision variable must be one. If not, it can be less or equal 1.
This is a simple example of integer optimization using solver.
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