Abstract: An artificially intelligent retirement income planning computing engine and methods for determining and documenting a withdrawal plan for a person who has multiple income sources. The computing engine has a data collection module to electronically receive a specification of cash flow receivable by the person from the income sources and a calculation module configured to employ multiple strategies employs rules-based artificial intelligence techniques to achieve a maximum or a pre-determined after-tax income that can be obtained by the person from the income sources during the person's retirement.