A process that loads all of the ideation into the early stages to the project, quickly narrowing multiple concepts down to what's perceived to be the most viable one. Each ensuing stage concentrates on refining the initially selected design.
Buxton’s variation based on the conventional design funnel is a simple concept: alternate between concept generation and controlled convergence. Unlike a traditional funnel, which encourages ideation only in the earliest phases of a project, this model embraces exploration during each stage. Concept convergence also occurs in each stage, whereby ideas are filtered down by measuring against explicitly defined design goals and principles. Controlling ideation with structured critique moves the design discussion towards actionable, productive feedback. This approach is healthy because it allows a greater number of ideas to be “suggested, proposed, and questioned.” The concept that no idea is sacred and that alternative, potentially better ideas may be introduced later int he process can only lead to a stronger product.
Because the assembly-line processes that result in a traditional design funnel have to kill so many ideas before they can be explored, there is a danger that they’ll come back to haunt you later. A stakeholder who is soured by the feeling that their idea wasn’t given due consideration might resist alternatives or seek to work in their idea at a later stage. Buxton’s variation, on the other hand, is more accommodating and fits well in a more iterative workflow.
So, what does all this talk about assembly lines and funnels have to do with designing for mobile? Simple: I don’t believe we front-load all of the necessary design decisions at the beginning of a project for any platform, least of all for mobile. This approach is an unfortunate remnant of industrial-era thinking, when products could be sequentially manufactured. We need to guide our clients to a shift in thinking about how we design and build software systems. We need to be able to make critical design and build software systems. We need to be able to make critical decisions about how an application behaves in the appropriate context, at different time throughout the project.
Photo credit: http://www.uxbooth.com/articles/concerning-fidelity-and-design/