Abstract: Described herein are methods and apparatus for performing an interactive, computer-implemented analysis of the sustainability of an investment portfolio to support a retirement income need for a client. In certain embodiments, the technology determines an optimum allocation of an investment portfolio in accordance with client goals, conveys a measure of the sustainability of the investment portfolio to provide sufficient income over the length of the client's retirement, allows adjustment of the portfolio by the client, determines a revised measure of sustainability, and provides information about the potential financial legacy that will be left to the client's heirs.