In traditional budgeting environments planning demand and thus revenues, has typically been a semi manual process. For example, an insurance company might model premium income by starting with policies currently in force, estimating attrition rates, forecasting new policies due to marketing efforts, and adding in the impact of increased or decreased premiums, in order to come up with projected policy volumes and premium income. This process relies upon the subjective judgment of someone who is reasonably expert in the particular insurance market.