Multi-commodity Network Flow (Transportation Problem)

Answered

Emmanuella Koranteng

December 18, 2020 05:46

• 
• 

I am new to Gurobi. I am solving a multi-commodity transportation problem. 2 products, 2 factories, 4 warehouses, and 4 retailers. I tried creating a multidict but when I run the model, it outputs 'infeasible model'. 

This is a part of it:

commodities, arcs, cost = gp.multidict({
('VCR-12','Rotterdam', 'Briston'): 24.4,
('VCR-12' ,'Rotterdam','Middlesborough'):25,
('VCR-12','Rotterdam', 'Liverpool'):24.5,
('VCR-12','Rotterdam', 'Brighton'):19.1,
('Blank tapes', 'Frankfurt', 'Frankfurt', 'Briston'):8.6,
('Blank tapes','Frankfurt','Middlesborough'):10.4,
('Blank tapes','Frankfurt','Liverpool'):10.2,
('Blank tapes','Frankfurt', 'Brighton'):7.5,

 

and the Model

TheBoscheimProblem = gp.Model()
units = TheBoscheimProblem.addVars(commodities, arcs, obj=cost, name="units")

 

but It keeps saying the Model is infeasible. How do I go about it?

Thanks

0

• Official comment

  

  Simranjit Kaur

  • Gurobi Staff

  June 23, 2025 03:03 Edited

  This post is more than three years old. Some information may not be up to date. For current information, please check the Gurobi Documentation or Knowledge Base. If you need more help, please create a new post in the community forum. Or why not try our AI Gurobot?.
• 

  Jaromił Najman

  • Gurobi Staff

  December 18, 2020 12:22

  Hi Emmanuella,

  You could compute an IIS to determine why your model is infeasible. The Knowledge Base article How do I determine why my model is infeasible? should be a good guide.

  Best regards,
  Jaromił

  0

Post is closed for comments.