Guaranteed Income is the amount of monthly income you must have and derived from your retirement assets amd most importantly your retirement budget which you established as you develop your retirement plan.  This amount will change over time but you must have a starting point.  Initially creating a flow of guaranteed income to meet minimum income requirements frees you to develop a better mor complex retirement allocation plan: arranging assets to achieve desired balance for desired income future liquidity needs, making allowances for inflation, special events and even bequests.  The key is to develop pots of money or assets for different uses starting with minimum financial requirements; know the amount, know where it will come from and know it will be there regardless of the economy, market or interest rates.