  Design systems represent a user interaction design and development approach
that is currently of avid interest in the industry. However, little research
work has been done to synthesize knowledge related to design systems in order
to inform the design of tools to support their creation, maintenance, and usage
practices. This paper represents an important step in which we explored the
issues that design system projects usually deal with and the perceptions and
values of design system project leaders. Through this exploration, we aim to
investigate the needs for tools that support the design system approach. We
found that the open source communities around design systems focused on
discussing issues related to behaviors of user interface components of design
systems. At the same time, leaders of design system projects faced considerable
challenges when evolving their design systems to make them both capable of
capturing stable design knowledge and flexible to the needs of the various
concrete products. They valued a bottom-up approach for design system creation
and maintenance, in which components are elevated and merged from the evolving
products. Our findings synthesize the knowledge and lay foundations for
designing techniques and tools aimed at supporting the design system practice
and related modern user interaction design and development approaches.
