Modeling begins by ASSUMING instead of deriving the future revenues and costs. Forecasts are the same as assumptions.
Forecasting simply EXTRAPOLATES the past data instead of making predictions I don't already know
Know the company's business model well, but cannot handle the COMPLEXITY of computing financial results from business actions
ONE-FITS-ALL financial ratios do not reflect correctly company-specific risks
Spend so much time generating SEPARATELY and then reconcile values between the three financial statements instead of deriving them consistently from the same source.