SRGM

Equation

Goel-Okumoto

$\mu \left(t\right)=0.0455790\left(1-{\text{e}}^{0.0001071t}\right)$

S-shaped

$\mu \left(t\right)=135.9\left(1-\left(1+0.002512t\right){\text{e}}^{-0.002512t}\right)$

Musa-Okumoto

$\mu \left(\tau \right)=1/-0.02648ln\left(\left(-0.02648\ast 0.05618t\right)+1\right)$

Song’s model

$\mu \left(t\right)=789.9226{\left(1-\frac{9}{9+\ln \left(\frac{789.9226+{\text{e}}^{0.0519t}}{1+789.9226}\right)}\right)}^{0.0519}$