Prior to retirement, I did finite element modeling of numerous structures and subassemblies for engineering structural analysis. We always backed up these project models on a daily basis to a remote drive or storage device in a separate building if possible. I would not want to recreate a month's work in a model development if the hard drive crashed. I did modeling of stud sill tank cars for train line coupler loads, truck induced car body bolster loads and positive and negative (Vacuum) pressures of the tank car shells as an example. Needless to say I back up my personal computer to an external hard drive at least once a week as a mininum.