Since its emergence in the early 1970’s, the soft systems design community of practice has been enabling non-technical persons to participate in collaborative problem-solving and design processes. It does so by way of processes strongly informed by systems thinking but scaffolded by visual models, physical prototypes, and conversation, rather than by precise definitions, math, and measurement.

One of its main such processes is the one presented here. You may well recognize it is the basis for much of what is called “design thinking” today. It is also referred to as the “double diamond” in many technical disciplines, including 21st century user experience design (UXD).

In project work, this process is very useful in modeling requirements and deliverables. It defines key moments in design and suggests appropriate stakeholders to engage in appropriate ways at those moments.

Here is a good clear introduction.