While agile methods and Human Centered Design (HCD) are similar in their emphasis on user research and iterative development, the two methodologies differ in their approach to how and when to apply various project roles.
Should developers be involved from the beginning, producing working software from the get-go for users to test? Or should projects begin with a discovery phase in which designers work with users to interpret needs before developers start?
Does the balance of talent change through the product development cycle?
These questions are tackled by Robert L. Read, a co-founder of 18F who has trained agile teams in federal agencies. Drawing on examples from Gov.UK and others, he explains the relationship between agile methods and HCD, and how the two can be successfully merged.
From the article:
A number of pitfalls can lead to a poorly-run HCD/Agile project. For example, developers sometimes do not produce testable functionality early in the project — either because they are giving technical problems and architecture higher priority, or simply can’t conceive of how to produce early testable functionality … It is a fundamental mistake because it gives the designers nothing to test with the users. It prevents iterating the design. It is the responsibility of the developers to use all of their creativity to produce … a high value of testable functionality to users as soon as possible.