The problem this paper addresses is the tension between descriptive and normative approaches to design theory and methodology. Descriptive approaches typically seek to document, formalize and/or automate existing ad hoc design methods, towards the goal of making current best practices available to all. In contrast, normative approaches attempt to improve upon existing design practices, towards a new method for how design should be done. Both approaches have strengths and weaknesses. This paper seeks to resolve some of the tension between the two approaches. It presents a new method for designing a design system that synergistically exploits the strengths while remedying the weaknesses of both normative and descriptive methods. An illustration that employs immersive computing technology (ICT) to remedy some of the cognitive biases that might occur in a normative mathematical model for disassembly planning is presented.