The inventive method for determining operational characteristics of a program includes a verification procedure involving the following stages: the first stage for expressing the operational characteristics of the program in the form of functions related to events producible during possible executions of the program, a second stage for simultaneously estimating, by program analysis, the program structure, the possible ways of execution and values used at different program points and the third stage for determining said characteristics by calculating associated functions by means of information extracted with the aid of the analysis.