1. A method for quantitatively analyzing risk for a risk-based testing of software having at least one module, the method comprising: assigning, for a set of test cases, a first confidence weight to each test case for each module based on its test history, the first confidence weight determined based on performance of a module in the set of test cases for at least one test cycle; determining an interaction value for an interaction parameter, the interaction parameter indicating the interaction of a module with remaining modules of the software; determining a usability value for a usability parameter, the usability parameter measuring an importance of the module for end-user operations; assigning a second confidence weight to each of a plurality of software specific parameter values for each module including the interaction value and the usability value for each module, the second confidence weight being a relative importance for the plurality of software specific parameter values to a module in the software; calculating, by a computing device, a raw confidence level for each module based on the assigned first confidence weight to each test case of each module; and calculating, by the computing device, a confidence quotient for each module by a formula that uses the raw confidence level and each software specific parameter value weighted by the second confidence weight for the module to calculate the confidence quotient, the confidence quotient for each module indicating the risk for defects in each module, wherein the confidence quotient is calculated by multiplying the raw confidence level by the interaction parameter in the software specific parameters to generate a first result, adding the usability parameter in the software specific parameters with a stability parameter to generate a second result, wherein the confidence quotient is calculated by adding the first result and the second result.