B.3.3:3.1 - Assurance subtypes answer different questions

Subtype	Code	Question answered	Contribution and boundary
Concept-Bridge Assurance	CBA	Do the load-bearing terms and participants correspond across the descriptions being used?	Compare the relevant meanings, referents and conditions through B.5.3 when movement across vocabularies can change the argument. A discovered or repaired mismatch can change the assurance conclusion. Performing a comparison does not itself improve a relation’s congruence.
Verification Assurance	VA	Does the claimed consequence follow under the stated specification and assumptions?	Inspect the proof, logical argument or applicable construction. The result supports that consequence under those premises; it does not establish that a running system satisfies its environmental assumptions.
Validation Assurance	LA	Does the empirical basis support the claimed performance in the receiving conditions?	Examine relevance, coverage, measurement quality, limitations and contrary results. A simulation supports a claim about its modelled conditions; transfer to an actual system needs the applicable model-to-world warrant.

Select the contributions needed by the claim, rather than demanding all three types for every judgement. A mathematical consequence may need a proof and no field trial. An engineering performance claim may have sufficient empirical support without an additional formal proof. A safety-related claim needs the actual protective argument and required evidence; neither FV ≥ threshold nor EV > 0 establishes that adequacy by itself.

Terms such as FV, EV or CL can be used only with the bearer, scale and interpretation the receiving argument consumes, as in B.3. A field called verifiedBy or validatedBy identifies a support relation to inspect, not a positive judgement by its mere presence.