Nk model for complex systems

Hi,
I am starting to read about Nk model as an Agent based tool to model economical phenomena. I wonder if this model can be useful for a big complex system with many and different agents.
How we can define rules in NK model?
Are their any ready framework for NK model or it requires to be built from scratch?

Any one have built NK for a large and complex system? I don’t know to what extent I can use this model!

Thanks & Regards
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