Presenting strategies in control policies, this text uses a systems theory approach to predict, simulate and streamline plant operation, conserve fuel and resources, and increase workplace safety in the manufacturing, chemical, petrochemical, petroleum, biochemical and energy industries. Topics of discussion include system theory and chemical/biochemical engineering systems, steady state, unsteady state, and thermodynamic equilibrium, modeling of systems, fundamental laws governing the processes in terms of the state variables, different classifications of physical models, the story of chemical engineering in relation to system theory and mathematical modeling, overall heat balance with single and multiple chemical reactions and single and multiple reactions.