In traditional AA designation, Al alloys have been designated based on main alloy elements.However, with modem alloy design tools such as computation aided alloy design, Al alloys could be developed beyond the traditional alloy designation.In the current work, examples of developed Al alloys will be presented: in 6xxx based alloys, introducing high Zn in addition to Si/Mg/Cu leads to preferred nucleation/precipitation competition, shorter ageing time and higher strength (both after paint bake cycle and in peak aged condition);introducing other key alloying elements (in addition to Mg) in 5xxx based alloys (combining the characterization of non-heat treatable and heat treatable alloys) lead to substantially improvement in IGC resistance, and higher strength due to precipitation hardening.Detailed discussion on precipitation mechanisms in multi-phase systems will be included.