Art is one thing, design is another. Artists are naturally designers. Their good eye for composition and white space, as well as their excellent understanding of color often gives them a headstart when they decide to venture into the science of design. But how well can an artist endure the obligation of functionality that science induces?
Art is liberal to some extent, and although most artists undergo rigorous discipline and restrictions at the beginning of their practice, they eventually burst out mid career with fresh, new approaches to existing rules, in order to 'find themselves'. Hence the common adage of doing things differently.
If artists like these eventually find themselves in the design discipline, a few challenges may surface.
Science is functional. Design is a science, therefore design must be fuctional, whilst being aesthetically pleasing. Design must fufill a purpose, solve a problem. Design must be useful. Literally.
Art neither has the obligation of fufilling aesthetics nor functionality in all facets. Art may solve problems, or in the least make the society aware of problems, but art is relative to the artist and/or his audience. Moreso, Art's functionality is not literal. Art's usefulness can be compared to that of tradition; we cannot see, touch or have any literal use for it, but without it, we will have no identity.
An artist who becomes a designer must put away liberal thoughts and actions, because design is for people to use. Before a design begins to be altered to look good, it must have fufilled the purpose for which it was made and satisfied the group of people which it will function for. Self expression and personal preferences must be subjected to real life uses and meaning.
This poses as a challenge, but when the rules of design, functionality and self expression have been fused, he is no longer just an artist. He is a scientist; he is a creator, he is a god.