Non-dominated Sorting Genetic Algorithm II (NSGA-II)

Non-dominated Sorting Genetic Algorithm II (NSGA-II) is a variant of MOGA that are designed to improve its previous version called Non-dominated Sorting Genetic Algorithm I (NSGA-I). NSGA-II was proposed by Deb to improve the efficiency of individual classification in NSGA-I. In NSGA-II, it generates a competing individual’s population and sort them based on their non-domination levels. It also applies the evolutionary operations to create a new offspring population which is the product of mutation among the parents. This algorithm is then conduct niching procedure by generating a crowding distance to each population member. The crowding distance is used to ensure a diverse population by making sure that each member stays within its crowding distance. This procedure keeps the population to be diverse and enhance the exploration of NSGA-II with higher diversity.