  We present an investigation into the spectroscopic properties of
non-equilibrium photoionization processes operating in a time-evolving mode.
Through a quantitative comparison between equilibrium and time-evolving models,
we find that the time-evolving model exhibits a broader distribution of charge
states compared to the equilibrium model, accompanied by a slight shift in the
peak ionization state depending on the source variability and gas density. The
time-evolving code, tpho in SPEX, has been successfully employed to analyze the
spectral properties of warm absorbers in the Seyfert galaxy NGC 3783. The
incorporation of variability in the tpho model improves the fits of the
time-integrated spectra, providing more accurate descriptions to the average
charge states of several elements, in particular for Fe which is peaked around
Fe XIX. The inferred densities and distances of the relevant X-ray absorber
components are estimated to be approximately a few 1E11 per cubic meter and
less than 1 pc, respectively. Furthermore, the updated fit suggests a potential
scenario in which the observed absorbers are being expelled from the central
AGN at the escape velocities. This implies that these absorbers might not play
a significant role in the AGN feedback mechanism.
