The most important stage in a product life cycle is the conceptual design which involves uncertainty but also opportunity. The SOS (Subjective Objective System) method of generating product design alternatives  is expanded here to introduce more information to help reduce uncertainty and explore design solutions to better suite customer requirements, market conditions, and the use of current technology. Hierarchical SOS uses two levels of building blocks: the 1 st level contains major building blocks (the same as in regular SOS) and the 2 nd level contains slightly more detailed articulations of the building blocks of the 1 st level. The product requirements are cascaded to the 2 nd level and are translated to secondary targets. The search of the best product design alternatives is done by a genetic algorithm (GA). As expected, the new information introduced and manipulated at the 2 nd level turns out to be critical for creating good conceptual designs of systems.