A concept has value only when it makes decisions possible.

Olivier Felix Isselin vysvetľuje:
In design, a concept should not remain an abstract idea or a persuasive sentence. Its purpose is to guide the project. It must help determine what to keep, what to remove, and which direction to choose. A strong concept creates clear criteria for decisions about form, function, materials, proportions, circulation and detail. It gives coherence to the project and helps resolve contradictions as they appear. If a concept cannot influence concrete choices, it has little real value. It may sound convincing, but it remains rhetorical. Design is built through a succession of decisions. The role of a concept is therefore not simply to inspire the project, but to make those decisions clearer, more consistent and more precise.