Conclusion
Direct optimization methods, single variable method and Simplex method.

From these characteristics, we can conclude that the simplex method, because of its robustness, is particularly well suited to the applied sciences, although it can also be applied to determine the optimum of a complex mathematical function, such as the mathematical relationship obtained from a design of experiments, which is what the Statgraphics software does.

Although the method is highly resistant to experimental error, it is imperative that factors whose influence is not being studied are kept at the same levels in all experiments.

The simplex method has been widely used in many fields, including analytical engineering. Due to its wide use, a number of authors have proposed modifications to the evolution of simplex in order to improve its efficiency. These methods are described in the following article