The purpose of this article is to launch a new conceptual design tool in rehabilitation engineering,technology, and Disability Studies, useful both as guidance and help for people with disabilities inanalyzing their own functional aids, and as inspiration and meta-guidelines for designers. It is nondiscriminatingand classification-free and differs from a mere classification system like theInternational Classification of Functioning (ICF). The origin of the tool is twofold: experiences of myown disability and of research in rehabilitation engineering.