A brief theoretical formulation is presented in order to determine the onset of plastic instabilities in both uniaxial and biaxial tensions in sheet metal type manufacturing processes. Besides, adiabatic shear band formation during ultra-high strain rates associated with very high speed deformation processes are discussed. In all these processes a significant portion of the energy input is wasted due to mechanical and thermal instabilities. The goal of the manufacturing industries is to minimize this enormous waste of energy by careful computation and numerical simulation of the processes like High Energy Rate Fabrication (HERF), including explosive forming, impact extrusion, high speed forging, ultra-high speed machining and grinding and many other emerging processes in the manufacturing industries involving mass production.