Working backwards from a goal prevents ideas from being locked-in by how people think about the problem right now.
In a way, thinking backwards from a goal is what people mean when they talk about first-principles thinking. The usual interpretation is to start with physics but I would assert that while tying back to physical laws is important to ‘first principles’ thinking, it’s actually the end. Or perhaps ending each step with checking “does this violate physics?” Is an important part of the process. Working backwards from a goal is ‘first principles’ thinking in the Aristotelian sense of not working off of the work of others, which is critical to working backwards.
The working backwards approach contrasts with the map-and-then-roadmap approach, where you would survey the entire landscape and then create a path through it. Roadmaps have two pieces - the map and the path . In reality, the approach is probably a deeply impure mixture of the two approaches - jumping back and forth between working backwards and describing the present state of the world. Understanding a thing has to do with intuiting the affordances of a thing and in order to understand the affordances of the area you’re playing in you need to at least engage with the way it does work now.
In a way there is a tension between working forward and working backwards. If you purely work backwards you ignore the accumulated wisdom of one or more disciplines, which is considerable if those disciplines are valuable in the first place. We stand on the shoulders of too many giants to give them all credit. And to compound the problem, often that wisdom (especially wisdom on the Knowledge frontier) is not well modularized and composable, so it’s hard to know what’s important and what’s ignorable without knowing it. At the same time, starting with “the state of a field” can be a trap in a couple of ways. The tech tree is fractal so you could actually spend an infinite amount of time digging into exactly what the frontier looks like. Additionally if you spend a lot of time immersed in current paradigms you’ll start to see the world through those paradigms, which is problematic for going after goals that almost by definition have not been reached by the people who work in those paradigms.
This tension between working backwards and forwards is embodied any time someone approaches a problem outside of their ‘area of expertise.’ It is perhaps best illustrated by physics. Physicists are constantly bombarded by theories from quacks who think that they have found a new theory of <life, the universe, and/or everything.> At the same time, people who in the past have found new theories have on occasion come from non-traditional backgrounds and were regarded as quacks, until they weren’t.
Perhaps the correct way to think about roadmapping is actually similar to a backpropagation algorithm, where you do many passes going both backwards and forwards. You
Not working backwards from a clear goal is one of the ways that Most roadmaps suck. A big reason they don’t do this is that working backwards is really hard. It forces you to consider important questions about something that doesn’t actually exist. Asking questions about “made up things” isn’t a mode of thinking we’re used to.
The Architected Innovation Institute - Engineering Scientific Revolutions asserts that working backwards from a goal helps you evaluate possible paths to that goal with an unbiased eye.
Treating Science Fiction as case studies from a future history might be one way to make considering important questions about things that don’t exist.
Thinking about hard-to-think-about questions regarding things that don’t exist seems like an actual place for tools for thought. You could build tools to make program design more efficacious.
Another framing besides ‘goals’ is answers to the question What does ‘working’ mean? for this particular program?
One thought is that perhaps you Work backwards with questions and work forward with answers?