CUST.3:1 - Problem frame

Use this method when several local solutions suggest a common contribution, when a current family has accumulated exceptions, or when a new offering needs a deliberate range of variation. The input may be completed cases, qualified component results or explicit prospective cases; their evidence status must remain distinguishable.

The first move is to compare the result and the conditions that make it obtainable, then propose what must remain invariant and what may vary. A list of similar requests, a shared codebase or a productization gate does not construct that family.

Keep a one-off solution local when there is no useful, supported common contribution. A known adequate family can be used directly through CUST.4.