Abstract: The present invention discloses a method for combinatorial layout design, in particular family mould layout design, using a computer. The method starts with receiving design specific parameters and information about moulding parts from user. A Genetic Algorithm module is then invoked to generate a population of layout designs which satisfies the design specific parameters. The Genetic Algorithm module first automatically generates a population of specially designed chromosome with three interdependent sessions. Crossover, mutation and replacement operation are applied on the population subsequently to evolve such towards a more optimal population over successive generations. In each generation step, a Genotype-Phenotype mapping module is utilised to decode the chromosome to corresponding layout design for fitness evaluation. A system for combinatorial layout design automation and optimisation using this evolutionary design approach is also disclosed in the present invention.