The absence of an applications led design philosophy has compromised both the development of laser source technology and its effective implementation into manufacturing technology in particular. For example, CO2 lasers are still incapable of processing classes of refractory and non-ferrous metals. Whilst the scope of this paper is restricted to high power CO2 lasers; the design methodology reported herein is applicable to source technology in general, which when exploited, will effect an expansion of applications. The CO2 laser operational envelope should not only be expanded to incorporate high damage threshold materials but also offer a greater degree of controllability. By a combination of modelling and experimentation the requisite beam characteristics, at the workpiece, were determined then utilised to design the Laser Manufacturing System. The design of sub-system elements was achieved by a combination of experimentation and simulation which benefited from a comprehensive set of software tools. By linking these tools the physical processes in the laser - electron processes in the plasma, the history of photons in the resonator, etc. - can be related, in a detailed model, to the heating mechanisms in the workpiece.