Concept design is the initial big picture or macro design. It shows us what problems the product will solve, how it will solve them, and what it will feel like as it is solving them. Arguably the most creative stage of product development, concept design is stickies slapped on whiteboards, ink and wash, and napkins and crayons even. It calls on us to consider sweeping ideas and all the various possibilities. The more the better. In concept design lies the very soul of innovation.