Design methodologies are systems or models that offer structure or consistency to focus on problems and drive success within a design process.
Methodologies help align all stakeholders within a project, an organization, or an industry. Some popular design methodologies include the product development life cycle (PDLC), double diamond diagram, design thinking, and user-centered design (UCD). These processes often emphasize an iterative, cyclical approach to design, incorporating user research to drive decisions from defining a problem to building a solution.
Over the years, organizations like Ideo, Google, and the Nielsen Norman Group, as well as people like Peter Morville, have defined some of the most popular methodologies for executing and assessing UI and UX design. New methodologies and principles are defined constantly within design — for example, design justice and Microsoft’s inclusive design emphasize diversity, equity, and inclusion.
Some designers or firms may specialize in specific methodologies, while others use a mixture of methods to suit a given situation or problem.