Solved and Future Constraints
An investor asks Kabir two questions. "Students have traded old books forever. Why can this work now?" And: "What will stop you reaching your vision?" Both questions are about constraints, the limits that shape what a product can do. One set explains why now; the other shows what is still in the way.
The rule
Solved constraints explain why now; future constraints show what still blocks you.
A constraint is anything that limits what the product can do: technology, cost, behaviour, rules, or the team's own reach.
Solved constraints are limits that have been removed, by the world or by your own work. They make the vision reachable today when it was not before. For ReShelf:
- Almost every student carries a smartphone with a decent camera, so listing a book takes seconds.
- Instant phone payments make a ₹300 handover simple, with no cash or change.
- ReShelf's own course-to-book catalogue for the pilot campus, built by hand, removes the edition guesswork.
Future constraints are limits that still stand between you and the vision. Naming them is honesty, not pessimism:
- Every new campus needs its own book list, collected by hand. That does not scale.
- Supply is lumpy: seniors sell at the end of the year, but first-years buy at the start of term.
- Colleges moving to digital course packs could shrink the printed-book market.
Each future constraint should carry a note on what would remove it and when it will start to bite.
The shortcut
For each constraint ask: "Why now, or what next?" Tag it solved if it explains why the vision is possible today, and future if it blocks the road ahead. Then give every future constraint a remover and a deadline.
"Students can pay each other instantly by phone"
This used to be a barrier: cash and exact change. It no longer is. Solved: part of why now.
The trap is hiding future constraints to make the vision look easier. They surface anyway, usually at the worst moment, and people stop trusting the vision.
Drills
Answer fast — trust the rule.
"Almost every student now has a smartphone with a good camera" is, for ReShelf, a:
"Each new campus needs its book list collected by hand" is a:
Why do investors and other stakeholders care about solved constraints?
What should accompany each future constraint in a vision document?
Remember
- Solved constraints explain why now; future constraints show what still blocks you.
- Ask "why now, or what next?", then give each future constraint a remover and a deadline.
- Trap: hiding future constraints to make the vision look easy.