Help Opmization Model Vehicle Routing Constraint

  • 18 November 2023
  • 1 reply


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!! :) 



Best answer by gdiepen 18 November 2023, 11:20

View original

1 reply

Userlevel 5
Badge +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’



Didn't find what you were looking for? Try searching on our documentation pages:

AIMMS Developer & PRO | AIMMS How-To | AIMMS SC Navigator