This work presents a mathematical model of the blown-film process. The model - part of a commercial software package - was developed with emphasis on the importance of temperature in the blown-flm process. This nonisothermal, purely viscous, temperature-dependent model was used to simulate bubble formation and the biaxial stretching of the film. Calculated results showed general agreement with a diverse set of experimental data, demonstrating that the model can successfully predict many important process parameters. The software can be used to draw many useful conclusions about almost any simulated blown-flm process.