Questions tagged [or-tools]
Questions related to or-tools, Google's open-source software suite for optimization
26
questions with no upvoted or accepted answers
6
votes
0
answers
203
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
0
answers
156
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 ...
4
votes
0
answers
653
views
Google-OR tools vs Pyomo and other commercial Solvers for solving a simple maximum flow problem
I have implemented a Pyomo model for solving maximum flow problem as a subroutine of an algorithm. However, the approach does not scale very well because Pyomo does not provide a very good way to re-...
- 392
4
votes
0
answers
101
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
0
answers
40
views
Adding synchronisation constraint in Prize-collecting VRPTW
I am solving a Prize Collecting VRPTW. In my problem, each node represents a visit that needs to be made within a certain time window, and the "prize" for each node is the time spent at the ...
- 33
3
votes
0
answers
193
views
Or-tools : CVRP multiple time window with multiple location
I am using or-tools to solve a CVRP with multiple time window, and multiple location.
Meaning that a customer can move during the day.
I can't achieve to add constraint like if i deliver the customer ...
- 31
3
votes
0
answers
166
views
Can Pyomo be linked with Google's GLOP or CP-SAT solvers?
Pyomo can be linked with several solvers Open source and commercial ones.
I was wondering if Pyomo can be linked with Google's GLOP or CP-SAT solvers?
- 1,235
3
votes
0
answers
451
views
Incorporating OR-Tools in a CMake Project
I'm trying to incorporate or-tools into my cmake project.
I've tried some of the suggestions given by the project maintainers, who give a few different ways to integrate or-tools in the readme and in ...
- 431
3
votes
0
answers
420
views
Circuit constraints in ortools
I am looking to assign tasks to people. Each successive task should be started after the first one is finished and should be started at the same location as the preceding task. While the time ...
3
votes
0
answers
279
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 ...
- 131
3
votes
0
answers
110
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 ...
- 139
3
votes
0
answers
148
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 ...
- 2,568
3
votes
0
answers
50
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 ...
- 31
3
votes
0
answers
179
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 $c_j$ ...
- 131
2
votes
1
answer
104
views
Control load per trip in multi trip VRP in ORTools
I have implemented multitrip VRP in ortools (To be specific, solved CVRPTW with virtual depots). Maximum number of trips per vehicle is limited to 2. I want to put a hard constraint that load carried ...
- 181
2
votes
0
answers
133
views
Multiple Depot/Crew Office Bus Driver Scheduling Modelling
I'm working on Bus Driver Schedule with multiple add-on constraints that are complex and hence trying to figure out how this can be achieved.
Reference of Bus Driver Scheduling using OR-Tools:-
https:/...
- 21
2
votes
0
answers
432
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 ...
1
vote
0
answers
57
views
How to cmpute IIS using the Or-Tools solver?
I'm trying to solve a MIP using Google Or-Tools, but it's showing that the model is infeasible. I'd like to know if there is a convenient way to analyze which constraint or variable bounds are causing ...
- 69
1
vote
1
answer
427
views
OR-Tools: Nonlinear constraints?
I have inherited a reasonably simple ortools-based optimizer (Python) with linear relationships that I need to non-linear-ize, and I have no idea how to do that.
The relevant part of my problem looks ...
- 119
1
vote
0
answers
90
views
Minimizing total number of banners used in the cover buildings problem modelled
I was watching a video about Google OR-Tools where they were solving this cover building problem from Codility challenges using constraint programming.
In short, you have a list of building heights, e....
- 111
1
vote
0
answers
280
views
Set Covering and Column Generation
I need some set covering and column generation examples in OR-Tools python.
If anyone can provide or direct me to some resources that would be great..!
- 137
1
vote
0
answers
192
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 ...
- 153
1
vote
0
answers
194
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:
...
- 111
0
votes
0
answers
128
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 ...
- 137
-1
votes
0
answers
50
views
Machine-state constraints for jobshop problem
Problem outline
I am trying to implement a job-shop problem using OR-Tools, which can be framed as a typical job-shop problem (minimize overall maketime of machines performing tasks) but the ...
-1
votes
1
answer
172
views
[OR-Tools][CP-SAT] Implement an indicator function in a constraint
Good morning ! I would like to implement this constraint using CP-SAT (see image below).
x_i,j is a boolean variable, a and b are given. The problem is that I don't know how to implement the ...
