Modelling and optimization of biological processes involve the using o
f numerical minimization techniques. It happens for instance when mode
ls have to be identified from experimental data. A functional dependin
g on n variables has to be minimized. Of course, the model and its opt
imization will be more convenient if we can suggest numerical techniqu
es giving a global optimum. We will describe in the following some num
erical techniques leading to the determination of a global optimum.