Solid-state welding processes are ideally suited for welding of aluminum alloys. Because these processes do not involve melting, the issue of weld solidification cracking does not arise. Among the solid-state welding processes, Friction Stir Welding (FSW) is very attractive for welding aluminum alloys. In any process the input parameters play a vital role in determining the output characteristics of the process. How to control the input process parameters is the common problem in any process. In order to overcome this problem, various optimization methods can be applied to define the desired output variables through developing mathematical models to specify the input and output variables. In this book Taguchi Method, Design of Experiments and Grey Relational Analysis are the main optimization tool to optimize the process parameters of Friction Stir Welding of AA 5083. As the process parameter plays a major role in the quality of welds, this books helps marine engineers and ship building industries to understand the dynamics of the FSW process parameter in welding of AA 5083.