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Help Opmization Model Vehicle Routing Constraint

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Hi Everyone,

I need help in implementing an optimization problem concerning the Vehicle Routing in AIMMS.

I am currently indiciating the constraints for the mathematical problem. The index i and j is for the customers or nodes and k is for the vehicles.

I now want to implement the constraint, that each vehicle can only leave the material-depot once. The material-depot i indicated by the value “0” for i or j.

The mathematical formulation is now: sum x(0,j,k) <= 1

In AIMMS it is indicated as follows: sum(j, x((0,j,k) <= 1)

In this case, the index i is directly indicated with the value 0 for the depot but wenn I integrate this formulation in AIMMS, I receive a warning: “The symbol 0 is not expected”.

How can I indicate this formulation in AIMMS in the correct way so that the system understands that “0” is the value for i?

Maybe someone can help me.. Thank you in advance!! :)

Userlevel 5
+7

The aimms formulation probably should be something like

sum(j, x( 0,j,k) )   <= 1

Depending on how you define the set where i and j belong to, you can either use the value 0 directly (if the set is a subset of integers) or you must put it between single quotes to tell AIMMS it is the element with the name ‘0’