Derive

a relationship between requirements. Often used to link requirements of different abstractions. This requirement is derived from this other requirement. Perhaps a functional requirement derived from a stakeholder requirement.

Depends

A relationship between requirements. Used when one requirement depends on another.

Necessity

One requirement is needed to also have the other. IE cafe needs an espresso machine only if the cafe needs to serve coffee.

Effort

One requirement makes another much easier. espresso machine needs 12v power routed to it, make install sandwich press (which also needs 12v power) much easier.

Satisfy

The inverse of derive.

Validate

relationship between a requirement and a way to test if the requirement has been completed or if the requirement adds value.