Analysis of the different factors which affect the improvement of high power laser systems are presented. It concerns ; the laser sources and their power and mode structure stability, their pointing stability and their efficiency, the beam transport and handling with different morphologies of machines according to the dimensions of the parts and the production rate ; the control of the industrial process through a central computer which takes in charge all the functions of the machine. Next, factors to be considered in the economical analysis for installing high power laser systems are discussed ; this covers the investment cost for the source and the associated system, the cost for consummables, for maintenance for training and labor. Comparison of the investment cost as function of power for both laser and electrons beam welding, shows that, generally speaking, there are two regions of beam power : the first located at less than 3 to 4kW where the laser is more advantageous economically, the second located at higher than 10kW where the E.B. is more advantageous. An example of a multi-stations mock-up (12 welding heads) supplied by a single laser beam is finally presented. Located at about 20m from the laser source the welding heads receive the laser beam through a distributor of high alignement precision. A spot weld similar to what is usually obtained with resistance spot welding can be achieved in about 0,5 second. Some technical and scientific problems relative to this application and concerning the transfer of laser beam are presented.