In this paper, two existing constraint handling approaches are compared. The constraint handling approaches are based on the same principle of preferring feasible solution candidates over infeasible but they differ in the case of two infeasible solution candidates. One approach calculates the sum of constraint violations, whereas the other approach uses Pareto-dominance of constraint violations. Comparison of the constraint handling approaches is done experimentally using Differential Evolution (DE) algorithm. DE, as many other evolutionary algorithms, contains control parameters to be set by the user. Besides using fixed control parameter values, also an Exponential Weighting Moving Average (EWMA) control parameter adaptation technique is used. Experimental results reveal that neither of the constraint handling approaches can be judged to be better than the other. What is surprising, also EWMA cannot be judged to improve performance when applied to constraints. It is rather causing more uncertainty according to the results.
