The mapping function takes average LGDs and "stresses" them to generate an input to the capital calculation that is better suited to the Basel II formulas and produces a more appropriate capital requirement.
However, I would suggest that bank management needs to enter these investments recognizing that the full benefits may not be gained quickly; may, if gained, be competed away; and may, indeed, not be captured at all. History teaches that costs may emerge long before expected revenues, and that operational risk can either decrease or increase as a result of making major technology investments.