[AMPL 25075] Request for Support in Fixing the Errors

Dear Team,

I am writing to request support with my model. I am trying to simulate a small system for a public call center, where multiple phone rooms are available, and people arrive to make calls. When a person arrives at the center, they are assigned a phone room. If all rooms are occupied, they wait in a queue. If the queue is full, the person is rejected. However, in my model, I first need to determine the appropriate number of phone rooms, waiting spaces, and supply capacity within an effective budget. In my model these variables are presented as: Appel_office_num, w_appel, and Soleil_cap. Then I can solve for the profit maximization.

I attempted to model this using a queuing process, but when running the simulation, I encountered errors such as:
“Variable in upper bound of range set”
“Variables in subscripts are not yet allowed…”

I was unable to resolve these issues and would appreciate any guidance on fixing them. Additionally, I would like to know if these types of problems require a specific solver.

I have attached my scripts for your reference. Thank you in advance for your support.

(attachments)

Test_case_2025_01_101.dat (2.18 KB)
Test_case_2025_01_101.mod (4.37 KB)
Test_case_2025_01_101.run (684 Bytes)