Thanks for the reply. Although the optimization can be performed by the external mean such as python or matlab, it seems to me that the results data still need to be extracted via CAD (i.e. fdtd-solutions -run script.lsf to export, I'd done that before) and there's no way to obtain the FoM without CAD supported. That's why I hope the command for engine-solver could be more flexible to be used. If there's any way to extract results without lsf or CAD but only with the engine-solver, plz let me know how. Thanks again.