2
votes
Will adding this constraint help my model?
I tried to test a simple example of what you proposed. I am setting an upper and lower bound $[0,5]$, $[0,4]$ to the variables $x$ and $z$ respectively. By turning off the pre-solving, heuristics, and ...
2
votes
Accepted
Will adding this constraint help my model?
I think the answer is a definitive "maybe". Adding constraint (3) might help the solver to recognize infeasible branches of the search tree sooner (branches with $\delta = 1$ where side ...
2
votes
Travelling salesman problem
The MTZ constraints are big-M constraints that enforce the logical implication
$$x_{ij}=1\implies u_j\ge u_i+d_j.$$
That is, if you traverse arc $(i,j)$, the cumulative demand at $j$ is at least the ...
1
vote
Accepted
Compute time between tasks
What you could do is the following: Introduce variable $t_{ij}$ that is the time between tasks $i$ and $j$. This variable is only defined for once per pair $ij$, therefore the $j >i$. Then, you can ...
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