Savings-to-Investment Ratio

The Savings-to-Investment Ratio (SIR) is the inverse of simple payback; for example, it is equal to the cost of the measure(s)/the anticipated $ savings (over its useful life). In this method, the higher the number is, the more attractive the technology is. A SIR of 1.0 is the breakeven point at which the investment pays for itself through the realized savings. An SIR score of more than 1.0 will result in a positive return on your investment over time.