Theory of Change An Essay by Aaron Swartz www.aaronsw.com A theory of change is the opposite of a theory of action — it works backwards from the goal, in concrete steps, to figure out what you can do to achieve it. To develop a theory of change, you need to start at the end and repeatedly ask yourself, “Concretely, how does one achieve that?” changegoals
Yagni A Definition by Martin Fowler martinfowler.com Yagni originally is an acronym that stands for "You Aren't Gonna Need It". It is a mantra from Extreme Programming that's often used generally in agile software teams. It's a statement that some capability we presume our software needs in the future should not be built now because "you aren't gonna need it". A late change in requirements is a competitive advantageRequirements proliferation softwareagilefeaturesplanning