First: sypathetically thinking

Compared to HAZOP, STPA and GSN based analysis more specialzed:
1.structurally notation for all potential circumstances group
2.control flow and logic flaws finding for those non-fault weakness, those weakness impact in design for hardware and software control logic change or small change for special factors
3.multifunctional analysis, unlike HAZEL on single functionality and as the ETA in 61508, SOTIF pay more attention in detail
- single functionality inssufficient, all chains potential like original hardware calculation capabilities not enough
- human misuse
- multi layer functionality
- potential chain of violation
-original design or Production to decommission and deposit phase detail confirmation
- OTA and related functionality change impact to SOTIF
- environmental influence
- AI not only in perception but as well in analyziz, judgement, arbitration etc
- Multi objects, globally as multi agent safety

SOTIF not only in ADAS but also in whole vehicle side, an important methodology to derive out design in the detail impact, we have to know this infrastructure information.

Second: HAZAOP

HAZOP based in isolated system

Third: STPA

STPA based on high complexity system full of control logic

For the analysis scope, we have to define all factors, like environment, climate, human interface, etc and functionality in decent granuality

For the control structure, we have to define the detail control structure in the item internally and itself in the vehicle side

For the unsafe control actions, the guide words
1.regarding human misuse, please refer to SOTIF guidwords

2.regarding potential control failures, we can use the FMEA, HAZOP, and ETA et

3.regarding identify loss scenarios, the scenarioa at last we have to check the block internally not externally

4.regarding cybersecuruity potential attack, define it in the 4 scope: physically, adjacent, local, and remote, and to evaluate the control structure if in the corresponding of the trusted environment

Forth: Main difference

1.STPA can derive out the scenarios and all of the potential hazardous event sequence comapred to HAZAOP

2.better multi layer functionality confirmation in different features, like as following:

3. better for identification in the vehicle architectures, the SOTIF identification of multi-features, multi-ECUs the requirements will be handled in the different ECUs, and impact in the FTTIs, and safety state, as MRC, MRM potential

4. in high level of level 4, level 5, autonomous driving, the STPA can discuss bout the human factors and perceptions in the detial scenarios. That is STPA---Failure scenarios---hazardous event sequence---vehicle level ---ECUs level

5. final, I have to confirm to some people, the STPA will derive out more hardware design and software design like common habits people using the bottle of water in the cabin, and potential problem the water will be drooped out the clusters, and that clusters shall have the anti-water proof requirements higher than quality requirements.

Thanks all.