# Each heuretic by default inherits the constraints affordances and assumptions of its parents # Each heuretic by default inherits the constraints affordances and assumptions of its parents For example: **Constraints** If a gear fails at 350degrees C, anything that uses that gear will fail at 350degrees C. Of course that constraint can be relaxed by another heuretic **Assumptions**For example, [[Polygonal modeling]] assumes that compute is relatively expensive and slow. So anything that builds on top of polygonal modeling has that assumption built in. This could possibly lead to contradictions which might suggest new ways of doing something. For example **Affordances** If an aluminum skin airplane can be used to fly 200 miles, you would expect a carbon-fiber skin airplane can be used to fly 200 miles. Of course, this is *by default.* Usually, a new heuretic differs from its parents in at least one of constraints, assumptions, or affordances. This is analogous to inheritance in object-oriented programming. ### Related * [[Design for roadmapping system]] * [[Constraints and assumptions are not directly observable in literature]] * [[§Tech Tree Model of Heuretics]]