"To revise the models" means to reexamine or modify the plans or ideas that have been developed. It could involve making corrections, changes, or improvements to the original models or theories. Full definition
A new revised model will be launched by the end of this month. (rediff.com)
This summer, two national education organizations will revise the model standards for the preparation, performance, support, and evaluation of school leaders. (edprepmatters.net)
They then estimated how much extra nitrogen and phosphorus would actually be available from natural sources and found that there would not be enough, revising the models accordingly. (sciencemag.org)