Sequence tool restriction

Answered

Susana Carmona

• April 08, 2022 19:36
• Edited

Hello everyone,

I have this data:

m = gp.Model('model')

jobs, tool = gp.multidict({

('A'): 1,
('B'): 1,
('C'): 2,
('D'): 3,

})

Where A,B,C,D are the jobs and 1,2,3 are the tools used for every a job.

 

I want to keep job A and B one after the other (sequence:  process A after B o viceversa) because they are using same tool. How can I create a restriction for set in a sequence the jobs that have same tool?

 

Possible solutions:

A-B-C-D

B-A-C-D

D-A-B-C

....

 

Thanks in advance!

 

 

0

• 

  Jaromił Najman

  Gurobi Staff

  • April 11, 2022 08:15
  • Edited

  Hi Susana,

  For modeling of the job sequence, you could consider introducing an auxiliary variable which represents A-B, i.e., something like \(x_{AB} = x_{A} + x_{B}\) (I am just guessing here). This way you don't have to deal with 2 variable when working with sequences. In the case that B-A is different from A-B, you might have to introduce 2 auxiliary variables for sequence modeling.

  Best regards, 
  Jaromił

  0

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