DFLUX subroutine (VDFLUX Subroutine) is used for thermal loading in various body flux and surface flux states in heat transfer and temperature displacement solvers when flux load is a function of time, place, or other parameters. In this package, you will learn “when do you need to use this subroutine?”, “how to use the DFLUX subroutine”, “what is the difference between DFLUX & VDFLUX?”, “how to convert DFLUX to VDFLUX and vice versa?”, and “How to use it in an example?”. Three workshops are presented so you can learn all these stuff in action: Simulation of welding between two plate with DFLUX subroutine, Simulation of Arc welding between two tube with DFLUX, and Simulation of different types of functional heat flux(Body-surface-Element) in plate with Johnson-cook plasticity with VDFLUX subroutine(Thermomechanical Analysis).