A method of determining the behavior of an electronic system comprising electronic components under variability is disclosed. In one aspect, the method comprises for at least one parameter of at least one of the electronic components, showing variability defining a range and a population of possible values within the range, each possible value having a probability of occurrence, thereby defining an input domain. The method further comprises selecting inputs randomly from the input domain, wherein the probability to sample (PTS) is obtained from the probability of occurrence (PTOIR). The method further comprises performing simulation to obtain the performance parameters of the electronic system, thereby defining an output domain sample. The method further comprises aggregating results of the individual computations into the parameter/variability of the electronic system and assigning a frequency of occurrence (FoO) to the resulting sample, the parameter variability and the frequency of occurrence defining the behavior.