Traditionally, the formal modeling of systems has been made via a mathematical model, which attempts to find analytical solutions to different problems. This enables the prediction of the behavior of the system from a set of parameters and initial conditions. Computer simulations build on are a useful adjunct to purely mathematical models.

Simulation can be defined simply as the act of representing some aspects of the real world by numbers or symbols which may be manipulated to facilitate their study. Simulation software or process simulator is a program that allows the user to observe an operation through simulation without actually running the program. It performs the following functions: automated calculations, material and/or energy balances, physical property estimations, design/rating calculations, process optimization.