The terms "Second-order Analysis" and "Direct Analysis" appear in many modern design codes but this use is still relatively new to engineers. In the past, second order analysis was mainly to account for sway effects and defined only as the second-order "indirect" analy-sis, P-Δ-only analysis or simplified second order analysis which needs to be used with the ef-fective length assumption. The modern second-order direct analysis or P-Δ-δ analysis allow-ing for both sway and member buckling effects with imperfections provides a reliable and proficient tool for practical design. Their underlying principle also carries a very different phi-losophy to the conventional design approach. This paper outlines the differences between the two design concepts. Several built structures designed completely without effective length assumption are also discussed. The era for re-Thinking our design and analysis philosophy seems to have arrived.