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 ...
A.Omidi's user avatar
  • 8,380
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 ...
prubin's user avatar
  • 37.8k
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 ...
RobPratt's user avatar
  • 30.4k
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 ...
PeterD's user avatar
  • 1,461

Only top scored, non community-wiki answers of a minimum length are eligible