Publisher Summary This chapter provides an intuitive understanding of the reasoning behind the choice of two heuristic search techniques, the genetic algorithm (GA) and simulated annealing (SA), to optimize the reservoir engineering problem. The existing production wells are identified by black circles. Now suppose that the optimization problem is to identify the subset of the five prospective injection locations which will maximize the productivity of the field, defined perhaps as the field's Net Present Value (NPV). The discretization of the decision variable is not done to simplify the problem. To the contrary, discretization actually complicates the optimization problem by making it difficult to apply the most efficient and powerful search techniques. Rather, the discretization is tolerated when it is the most natural representation of the real-world problem to be solved.