B.3.3:7 - Rationale

A claim, argument and evidence have different functions. Assurance improves when a contribution closes a relevant gap under applicable assumptions. Counting evidence types or increasing formality cannot guarantee that improvement.

B.3 supplies this claim-and-use structure and its source account. ISO/IEC/IEEE 15026-2:2022 concerns the structure and maintenance of assurance cases. This pattern adapts maintained, inspectable support to a receiving use; its subtype distinction and optional level profiles are FPF choices, not a level ladder attributed to that standard. Reconsider a local profile when its evidence model, receiving decision or threshold basis changes.