Accelerated life family
= Accelerated life family
{title2=$S_z(t)=S_0(t/c_z),\quad c_z>0$}
An accelerated life family consists of <survival distributions> related by positive time scaling: $T_z$ has the distribution of $c_zT_0$. Therefore the <survivor function> is $S_z(t)=S_0(t/c_z)$ and, for densities, the <hazard function> is $h_z(t)=c_z^{-1}h_0(t/c_z)$. This need not be a constant hazard ratio.