Systems thinking's influence on design is relevant in modern society. Systems are identifiable everywhere in nature and the developed world. A system has interrelated elements whose relationships are both structural and functional. A complicated example of how a systems approach can be used in the design process is in seeking a solution to problems that are complex, unique, and not reducible to smaller sub-problems. These types of problems are called wicked problems. Deciding which aspects of a wicked problem should be focused on is done through human judgment. A designer or design team can use a systems approach to shape design judgment in creating a solution to this kind of wicked problem. However, using a systems approach, a wicked problem can be reframed from an irreducible situation to a design situation. Harold Nelson combined a multitude of systems models, theories, approaches, and methods into an actionable framework.