Predicted Z − SFR relations for different model configurations. First panel: model 1, incorporating inflow but no outflow, with ϵ_SF as the varying parameter. Second panel: model 2, incorporating outflow but no inflow, with ϵ_SF as the varying parameter. Third panel: model 3, incorporating both inflow and outflow, with η as the varying parameter. Fourth panel: model 4, incorporating both inflow and outflow, with β as the varying parameter. In all panels, the lines are color-coded by stellar mass, while different line styles indicate variations in model parameters.