Whenever a function or a relationship within a living system can be described mathematically, the possibility exists for developing a mathematical model. Scientists have long employed such models in biological and medical research because they provide the opportunity to vary the parameters involved and to predict what effects different parameters will have on the system. A complete inventory of information and parameters that should go into a model is not available until after extensive experimental work has been done on a living system. In addition, the final stage of this process must be to go back to the organism to check the accuracy of the model's predictions.

It has been suggested that computer technology is now so advanced that computer based models can completely substitute for the use of animals in research. Computers analyze data; they do not generate it. To make use of a computer model a researcher or instructor must supply the computer with whatever information is needed for the model. If a living system is being modeled, the only source of this information is the living system itself. The more detailed the information supplied to the model, the better the model is likely to be. Based on information derived from animal studies, computer models have been developed to analyze relationships within and between living systems. Computer models have been particularly useful in modeling feedback systems. In animal behavior, for example, game theory has been used to construct computer models which would predict how animals might behave during aggressive encounters. Biomedical applications of computer models include aspects of kidney, cardiac and lung function, regulatory systems, endocrine function, sensory physiology, neurophysiology and developmental biology.

Biochemical applications of computer models include recognition programs to identify toxic substances. Similar attempts to identify carcinogens by computer have, so far at least, been less successful.