At the beginning of a UX research and design project a Stakeholder Interview should be conducted to find out the Business Goals, Existing Research including User Research, Competitors and Technological Limitations.
Interviews
Stakeholder Interview — UX Knowledge Base Sketches
The goal of accessibility is to design & code digital products, services in a way that users with disabilities are able to use them. Your context or temporary condition and limitation also affect the way you use a product.
Agile is an iterative approach to project management and software development that helps teams deliver value to their customers faster and with fewer headaches. Instead of betting everything on a "big bang" launch, an agile team delivers work in small, but consumable, increments. Requirements, plans, and results are evaluated continuously so teams have a natural mechanism for responding to change quickly.