This paper presents a phenomena-driven process design method that uses kinetic and thermodynamic knowledge to propose structural and operational design alternatives. Continuos parameters of design alternatives are described at different accurateness levels : Boolean values, numerical ranges and numerical values. The method makes a strict division between tasks that determine what is desired, and where, when and how it can be achieved. In this way the decisions to be taken are more clear and the decisions taken in a previous design case are better understood. The method is used as the requirements specification for an interactive knowledge-based system in which different types of knowledge are integrated and that operates in an automatic or support mode.