What is CEI

This chapter addresses some issues related to some Optimal Control Theory (OCT) problems (for example, impossible analytical solution because of an unsolvable integral, or punctual parameters that were unrealistic). It is proposed the use of OCT as a benchmarking tool to analyze inventory control systems to enhance parameters. In addition, the application of methods and heuristics in solving these problems is also described. These methods are discussed and applied in calculating the production and inventory functions using data of accounting variables of USA and Brazil companies, available in the Economatica software data base. Eventually, the results are compared and some recommendations about the advantages and disadvantages of each method are accomplished.