I create a mathematical model of your optimization problem to describe a complicated real-world decision task in terms that are accessible to the computer. Such a model comprises decision variables, constraints, and an objective function. The decision variables describe the nature of each partial decision; for example, yes/no, a number of entire units (such as trucks used), and the amount of some continuous good (such as electrical energy).
Constraints are (e.g., thermodynamic) linkages of the decision variables, as well as situation-specific logical, legal, and strategic restrictions on the overall decision. For example, a well-trained employee can operate three different machines, but at most one at a time. Together, we describe your quality and safety requirements, collect data and process flows, as well as idiosyncrasies of potentially aged plant systems that have been steadily expanded. The objective function is a formula that assesses the quality of a decision. As an example, production costs of processes with time variable costs can be used to assess a production plan.