Multi-objective optimization (also called Multi-objective programming or multi-criteria optimization) being a branch of mathematical optimization dealing specifically with optimization problems having several objective functions. It is with the aim of knowing how to deal with these kinds of problems that we have approached in a current subject the notions of multi-objective optimization, the performance criteria of multi-objective algorithms, the constraints and penalty functions and the balance between convergence and diversity. Thus, the object of this project and to be able to solve single-objective and multi-objective problems using the JMetal library in java.