Questions tagged [or-tools]

Questions related to or-tools, Google's open-source software suite for optimization

13 questions with no upvoted or accepted answers
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7
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230 views

OR-TOOLS : delivery node with multiple possible pickup nodes

I am using ortools to model a VRP with pickup and delivery constraints, where pickups can be done at different nodes. For example, if node A has a demand, it must be picked at node B or C. Here is how ...
6
votes
0answers
114 views

OptionalIntervalVar enforced but not working OR-TOOLS

I'm using OptionalIntervalVar and then maximizing the starts. The optimal solution is not affecting the other variables that creates the ...
6
votes
0answers
118 views

Modelling issue with precedence constraint in OR-Tools

I'm trying to solve an RCPSPDc model It is infeasible, although Ilog Cplex solves it, so I think I have a modelling issue. I have more constraints but the precedence is the one that makes it ...
5
votes
0answers
80 views

Modelling issue with rcpsp and boolean expressions

I'm trying to solve an RCPSPDc problem in OR-Tools with CP-SAT solver. In my RCPSPDc model (with discount rate) i want to set this objective: $$\max_{s}\sum_{j\in J}\text{profit}_{j}\cdot \frac{1}{(1+...
3
votes
0answers
102 views

Production planning for a video game economy

I'm a software developer who likes to play a video game that has a complex economy. I realized that the type of problem I'm trying to solve mimics real life operations research problems, and I am ...
3
votes
0answers
78 views

Best known results on the flexible jobshop benchmarks

Is there a website that compiles the best known results on the flexible jobshop problem ? I know there was a blog post/article by Quintiq, a (deleted) blog post on CP Optimizer, some more recent ...
3
votes
0answers
106 views

Power of variable or tools

I'm working with OR Tools in Python and I need to define the objective function an expression of the variables. In particular, the objective function is $$\frac{c_j}{1.7^{s_j}}$$ with $c_j$ ...
2
votes
0answers
34 views

Add Variables in Bulk for ortools

I am using the Python ortools to solve large LPs where the number of variables and constraints are in the hundred thousands ($10^5$). Surprisingly, it takes longer ...
2
votes
0answers
139 views

modify pickup and delivery problem to only delivery scenario in google OR-tools

I am using Google OR Tools for solving the capacitated vehicle routing problem.I want to implement optimization solution for delivery problem.For example there is one storage location which load all ...
2
votes
0answers
42 views

High-mix manufacturing capacity

I'm not an expert in OR but I would like to determine what is the maximum manufacturing capacity of a plant (or how much a plant can produce of mix products). Each person in the plant has a known set ...
1
vote
0answers
36 views

Modified bus scheduling problem question in ortools

Has been crossposted in stackoverflow. I want to solve the bus scheduling problem using ortools with some minor modifications. In my case, the max number of drivers is known. The modifications I would ...
1
vote
0answers
67 views

Fixed cost associated to SlackVar(waiting time cost) [CVRPTW]

I'm modeling a CVRPTW with some features: Each type of vehicle has a cost per km and a fixed cost per trip. To calculate these costs, I am using these methods for this: ...
0
votes
0answers
77 views

Mixed Integer Programming - Model Formulation for A Resource Allocation Problem

There are a number of orders, which needs to be shipped. For each order, there may be 1 to 3 route options. The problem here is to find out the best allocation (combination) of orders among these ...