This paper describes two optimisation methods which can be applied to the parameter selection stage of Fluid Power System design. These two methods used are a Genetic Algorithm (GA) and a Tabu Search method, both of which have been claimed to be truely global methods. GAs are a method inspired by natural selection and Darwinian evolution whilst Tabu Search is an aggressive search metaheuristic which guides local search methods towards the globally optimum solution. Results are presented for two different circuit optimisation tasks. These results show that each of the two methods have both advantages and disadvantages.