In this paper, we present what is Behavioral Testing, the motivation in Behavioral Testing and how to perform Behavioral Testing. A new BTPG approach for circuits described according to a behavioral point of view in a procedural way is detailed. By using an internal modeling allowing the main features of behavioral descriptions to be highlighted, our approach is independent from a particular HDL used to describe the circuit behavior. Furthermore our approach is also general enough to deal with any abstraction level. The approach we propose to generate test patterns consists into two steps: the first one is to define a resolution approach by identifying and solving the basic problems setting up by the behavioral generation without any optimization criteria. The second step is to study how the previous resolution approach can be performed by a technique allowing the generation system to be flexible and evolutive in order to introduce optimization criteria. By such an approach, we avoid the detrimental a priori determination of a single search strategy. Such an approach has led to the development of BETEGE, a behavioral test generation system for procedural descriptions.