In order to make the designing of product variants more effective and efficient by automating the process, there is a need to break down and analyse the design process. In doing so, a clearer picture of the actual process will emerge. From this, a problem definition and a system specification can be outlined. This paper presents one such case of breaking down a design problem, defining its process character and capturing its inherent domain knowledge. This is then mapped to suitable tools and computer implementations. One of the tools chosen in this work, Case Based Reasoning, is further addressed, together with some implementation issues concerning CBR. Finally, advantages of a variant design approach to setting up CBR indexing templates are presented.