Heuristic
Separate opposite requirements in time
Two incompatible requirements can coexist if they stop competing for the same time slot.
When it fits
- The same element needs opposite states, but not necessarily at the same moment.
When to avoid it
- Time separation fails when both properties are truly required at the same moment or transition latency creates unacceptable risk.
Why it matters
Ask when each opposite property is actually needed. Create distinct phases, transitions or modes so the element satisfies A during one interval and not-A during another. Make the switching trigger explicit and check the transition cost.
An example
A deployment pipeline can move quickly through low-risk automated checks, then slow into a monitored bake period only after production exposure begins.
Check your result
The opposite requirements no longer apply simultaneously, and the switching rule can be executed or tested.
Keep this limit in mind
- Time separation fails when both properties are truly required at the same moment or transition latency creates unacceptable risk.
Evidence and sources
Classical TRIZ lists separation in time, separation in space and separation upon condition among methods for resolving physical contradictions.
These are solution-search heuristics; implementation still needs domain evidence, safety and feasibility checks.
Contradictions · Methods for resolving physical contradictions