The Rational Model
the design process is plan-driven,
the design process is understood in terms of a discrete sequence of stages.
The Rational Model is based on a rationalist philosophy and underlies the Waterfall Model, Systems Development Life Cycle and much of the engineering design literature. According to the rationalist philosophy, design is informed by research and knowledge in a predictable and controlled manner. Technical rationality is at the center of the process.
The Action-Centric Model
The Action-Centric Perspective is a label given to a collection of interrelated concepts, which are antithetical to The Rational Model. It posits that:
the design process is improvised,
no universal sequence of stages is apparent – analysis, design and implementation are contemporary and inextricably linked
The Action-Centric Perspective is based on an empiricist philosophy and broadly consistent with the Agile approach and amethodical development. Substantial empirical evidence supports the veracity of this perspective in describing the actions of real designers. Like the Rational Model, the Action-Centric model sees design as informed by research and knowledge. However, research and knowledge are brought into the design process through the judgment and common sense of designers – by designers "thinking on their feet" – more than through the predictable and controlled process stipulated by the Rational Model. Designers' context-dependent experience and professional judgment take center stage more than technical rationality.
Every project I do, I start out using the Rational Model. Then all hell breaks loose, and I switch to the Action Centric Model, and as I finalize the project, I go back to the Rational Model. What's the best model (if there is one) for the GRAPHIC design process?