I faced a weird question:what is the requirement of having a wave equation for the QM systems? I think unless we have it,we cannot predict the probabilistic time and space evolution of the wave function subjected to potential constraints.(dynamicity of the wave function will be lost). However,this does not help us to see the effect of performing measurements on the wave function... Any point missing??? Another thing: The essential features of this equations should be: (i) Should be consistent with statistical interpretation of wave function (ii) [tex]\psi[/tex] should be normalized all the way (iii)The equation should be consistent with correspodence principle Any suggestion???