An analyst working at a fixed-income investment firm is evaluating different approaches the firm uses to determine the Value at Risk (VaR) for its corporate bond portfolios, which are made up of a wide range of bonds with varying maturities. One method the analyst is contemplating is the use of a mapping technique to simplify the VaR estimation process. Which of the following statements would be correct for the analyst to assert regarding the mapping methods for fixed-income portfolios?