CODEWITHSUNDEEP
optimizationor-toolscp-sat
Artem
Artem

Reputation: 33

Setup times in a Job shop scheduling problem

I am working on an application of the google or-tools to a scheduling problem. I am pretty satisfied with the cp_model api, still it seems to lack some functionality only available in the vehicle routing module pywrapcp.

Here is the basic example of a program utilizing the cp_model module available on the official page: https://developers.google.com/optimization/scheduling/job_shop#entire-program

My question is: would it be somehow possible to introduce the setup time dimention in the above code as we would do in a regular TSP problem like this:

    def distance_callback(from_index, to_index):
        """Returns the distance between the two nodes."""
        # Convert from routing variable Index to distance matrix NodeIndex.
        from_node = manager.IndexToNode(from_index)
        to_node = manager.IndexToNode(to_index)
        return data['distance_matrix'][from_node][to_node]

    transit_callback_index = routing.RegisterTransitCallback(distance_callback)

    # Define cost of each arc.
    routing.SetArcCostEvaluatorOfAllVehicles(transit_callback_index)

The only close example found was this one: https://github.com/google/or-tools/blob/stable/examples/python/single_machine_scheduling_with_setup_release_due_dates_sat.py However, it seems to be working only with one machine.

Upvotes: 0

Views: 1252

Answers (1)

Laurent Perron
Laurent Perron

Reputation: 11064

There are 3 examples to describe setup times:

Upvotes: 0

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