The purpose of this communication is to provide constraint based generic modeling elements, for industrial product in order to design knowledge bases for configurators. After a brief introdcution, the presentation is divided in three parts. The first one recalls the main trends of the configuration problem and introduces the generic modeling need. The second one presents modeling elements for what we call the "central problem". The last part adds some important elements to the central problem with complementary modeling elements. An example of a storage system provided by the Lapeyre company illustrates the presented concepts.