Functional Safety Concept — Assumed FSRs

Derived from ASG_0001 / ASG_0002 per ISO 26262-3 §8. Each AFSR carries the post-decomposition ASIL of Element A: ASIL B(D).

The AFSRs are assumed — they describe the item-level functional safety obligations that an integrator’s real item HARA must confirm (AOU_0006). Taktora’s own technical refinement onto its crates lives in Technical Safety Concept — TSRs.

Assumed Functional Safety Requirement: Spatial Freedom From Interference between integrity levels AFSR_0001
status: assumed
asil: B(D)
refines: ASG_0001, ASG_0002
is refined by: ADR_0050, TSR_0003, TSR_0009

Taktora shall enforce spatial Freedom From Interference between safety-critical hosted items and QM-grade hosted items co-located in the same workspace, such that no QM-grade item can mutate the address-space or in-memory state observed by a safety-critical item.
Assumed Functional Safety Requirement: Directional channel topology AFSR_0002
status: assumed
asil: B(D)
refines: ASG_0002
is refined by: ADR_0050, TSR_0005, TSR_0007, TSR_0008, TSR_0009

Taktora shall enforce channel directionality on all inter-item shared-memory communication, such that a reader of integrity level L_r can only receive data from a writer of integrity level L_w >= L_r.
Assumed Functional Safety Requirement: Per-integrity-level allocation isolation AFSR_0003
status: assumed
asil: B(D)
refines: ASG_0001
is refined by: ADR_0051, TSR_0001, TSR_0002

Taktora shall isolate memory-allocation failures between integrity levels, such that allocation pressure from QM-grade items cannot cause a safety-critical item to encounter an allocation failure it would not otherwise have encountered.
Assumed Functional Safety Requirement: Internal fault detection and propagation AFSR_0004
status: assumed
asil: B(D)
refines: ASG_0001, ASG_0002
is refined by: TSR_0004, TSR_0006, TSR_0008, TSR_0010

Taktora shall detect and propagate internal framework faults — allocator exhaustion, missed deadlines, connector disconnect, item panic, channel corruption — to an integrator-observable surface within FTTI/2 (at most 50 ms given the assumed 100 ms FTTI).
Assumed Functional Safety Requirement: Startup integrity verification AFSR_0005
status: assumed
asil: B(D)
refines: ASG_0001, ASG_0002

Taktora shall verify that the spatial-isolation context is intact before admitting a safety-critical item into the executor’s runnable set on each cold start.