Rapid Iterative Testing and Evaluation or RITE is a process I've used while working at Yahoo! and Google to quickly make progress on new product designs and give teams a deeper shared understanding of the problem space they're working on.
RITE is basically a continuous process of designing and building a prototype, testing it with users, and making changes within a short period, typically a few days. The goal is to quickly identify and address issues, and then iterate on the design based on the what was learned. This gives teams regular face time with end users and collectively grows their knowledge of the needs, environments, and expectations of their customers.
The way I've typically implemented RITE is every Monday, Tuesday, and Wednesday, we design and build a prototype. Then every Thursday, we bring in people to use the prototype through a series of 3-5 usability tests that the whole team attends. On Friday, we discuss the results of that testing together and decide what to change during the following week. This cycle is repeated week after week. In some cases running for months.
This approach puts customers front and center in the design process and allows for quick adaptation to issues and opportunities each week. The RITE method is also useful because it provides insights not just opinions. In other words, if there's a debate about a design decision, we can simply test it with users that week. This squashes a lot of open-ended discussions that don't result in action because the cost of trying something out is incredibly low. "OK we'll try it."
The cadence of weekly user tests also really aligns teams on common goals as everyone participates in observing problems and opportunities, exploring solutions, and seeing the results of their proposals. Over and over again.