Hi everyone! i have a model with a set aircraft:={1…N}, which describe an aircraft landing problem. My objective is to decompose the problem into subproblems that are easier to solve individually. I want to create subsets of aircraft, solving smaller subproblems separately and then combining the solutions, reducing the overall computational complexity and obtain good solutions more quickly. To do this, i have implemented this algorithm which iteratively generates the subsets ‘aircraft-relaxed’ and, for each subset, solve the new model ALP_red (this model is equal to the initial one, but instead of set aircraft, it uses set aircraft_red, for each variables and constraints). The problem is that AMPL gives me an error if i put the model ALP_red inside the for cycle. How can I solve this problem, in order to achieve my goal?

Attached the initial model ALP_model, the new model ALP_model_red, and the file .run which represents my algorithm (decmat.run)

Thank you for your help!

Best regards, Andrea

ALP_model.mod (2 KB)

alpdec.mod (2.29 KB)

decmat.run (1.45 KB)