Circularity Issue in Financial Modelling of Infrastructure Projects

One of the most frequently occurring issue in Project Finance Model is the circularity problem. Most frequently we encounter this during linking of IDC (Interest During Construction) to TPC (Total Project Cost). TPC and IDC are interdependent and hence the circularity error. I have seen models which resort to complicated calculations and Macros to resolve this issue.
In reality, there is a very simple technique to address this problem. In the Excel sheet, Go to File>Options>Formula and enable Iterations on the Top Right. The excel automatically enables iterations and resolves the circular error issue. Please do this at the beginning of building the model.