Genetic algorithm
Repeated fitness function evaluation for complex problems is often the most limiting segment of artificial evolutionary algorithms. Finding the optimal solution to complex problems often requires very expensive fitness function evaluations. In real world problems such as structural optimization problems, a single function evaluation may require several hours to several days of complete simulation. Typical optimization methods cannot deal with such types of problem. It is often necessary to use approximation, as calculating the exact solution takes too long. Genetic algorithms sometimes combine different approximation models to solve complex real life problems.