Demo page details

Page source code: analysis.rst

  1{% set page="analysis.rst" %}
  2{% include "demo_page_header.rst" with context %}
  3
  4📊 Safety Traceability Analysis
  5================================
  6
  7This page provides comprehensive visualization and analysis of the complete safety
  8artifact traceability chain from hazards through safety goals and functional safety
  9requirements to system requirements.
 10
 11Complete Safety Traceability
 12-----------------------------
 13
 14This diagram shows the complete traceability from the top-level hazard through all
 1520 safety goals, 30+ functional safety requirements, to 18 system requirements.
 16
 17.. needflow::
 18   :tags: safety_example
 19   :types: hazard,safety_goal,fsr,sysreq
 20   :show_link_names:
 21   :link_types: mitigates,derives_from,implements
 22   :scale: 80
 23
 24Safety Artifacts Overview
 25--------------------------
 26
 27Complete list of all safety artifacts with key metadata.
 28
 29.. needtable::
 30   :filter: docname is not None and "safety_example" in docname
 31   :columns: id, type_name, title, asil, status
 32   :style: table
 33   :sort: type
 34
 35ASIL Distribution Analysis
 36---------------------------
 37
 38Distribution of Safety Artifacts by Type
 39~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 40
 41.. needpie:: Safety Artifacts by Type
 42   :labels: Hazards, Safety Goals, FSRs, SYSREQs
 43
 44   type == "hazard" and docname is not None and "safety_example" in docname
 45   type == "safety_goal" and docname is not None and "safety_example" in docname
 46   type == "fsr" and docname is not None and "safety_example" in docname
 47   type == "sysreq" and docname is not None and "safety_example" in docname
 48
 49Safety Goals by Subsystem
 50~~~~~~~~~~~~~~~~~~~~~~~~~~
 51
 52.. needpie:: Safety Goals by Subsystem
 53   :labels: VDC, WRDC, Drive, Brake, Steering
 54
 55   type == "safety_goal" and docname is not None and "safety_example" in docname and (id == "SG_01" or id == "SG_02" or id == "SG_03" or id == "SG_04")
 56   type == "safety_goal" and docname is not None and "safety_example" in docname and (id == "SG_05" or id == "SG_06" or id == "SG_07" or id == "SG_08" or id == "SG_09" or id == "SG_10" or id == "SG_11" or id == "SG_12")
 57   type == "safety_goal" and docname is not None and "safety_example" in docname and (id == "SG_13" or id == "SG_14")
 58   type == "safety_goal" and docname is not None and "safety_example" in docname and (id == "SG_15" or id == "SG_16")
 59   type == "safety_goal" and docname is not None and "safety_example" in docname and (id == "SG_17" or id == "SG_18" or id == "SG_19" or id == "SG_20")
 60
 61FSRs by Subsystem
 62~~~~~~~~~~~~~~~~~
 63
 64.. needpie:: FSRs by Subsystem
 65   :labels: Steering, Brake, Drive, WRDC, VDC, Sensors, Power, Process
 66
 67   type == "fsr" and docname is not None and "safety_example" in docname and id.startswith("FSR_STEER")
 68   type == "fsr" and docname is not None and "safety_example" in docname and id.startswith("FSR_BRAKE")
 69   type == "fsr" and docname is not None and "safety_example" in docname and id.startswith("FSR_DRIVE")
 70   type == "fsr" and docname is not None and "safety_example" in docname and id.startswith("FSR_WRDC")
 71   type == "fsr" and docname is not None and "safety_example" in docname and id.startswith("FSR_VDC")
 72   type == "fsr" and docname is not None and "safety_example" in docname and (id.startswith("FSR_VEHICLE_SENS") or id.startswith("FSR_WHEEL_SENS"))
 73   type == "fsr" and docname is not None and "safety_example" in docname and id.startswith("FSR_POWER")
 74   type == "fsr" and docname is not None and "safety_example" in docname and id.startswith("FSR_PROC")
 75
 76Critical Path Analysis
 77-----------------------
 78
 79Vehicle Dynamics Controller Critical Path
 80~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 81
 82Traceability from hazard through VDC safety goals to VDC FSRs.
 83
 84.. needflow::
 85   :filter: (id == "HAZ_TRAJ_DEV") or (type == "safety_goal" and (id == "SG_01" or id == "SG_02" or id == "SG_03" or id == "SG_04")) or (type == "fsr" and id.startswith("FSR_VDC"))
 86   :show_link_names:
 87   :link_types: mitigates,derives_from
 88   :scale: 90
 89
 90Wheel Rotational Dynamics Controller Critical Path
 91~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 92
 93Traceability from hazard through WRDC safety goals to WRDC FSRs.
 94
 95.. needflow::
 96   :filter: (id == "HAZ_TRAJ_DEV") or (type == "safety_goal" and (id == "SG_05" or id == "SG_06" or id == "SG_07" or id == "SG_08" or id == "SG_09" or id == "SG_10" or id == "SG_11" or id == "SG_12")) or (type == "fsr" and id.startswith("FSR_WRDC"))
 97   :show_link_names:
 98   :link_types: mitigates,derives_from
 99   :scale: 90
100
101Steering System Critical Path
102~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
103
104Traceability from hazard through steering safety goals to steering FSRs.
105
106.. needflow::
107   :filter: (id == "HAZ_TRAJ_DEV") or (type == "safety_goal" and (id == "SG_17" or id == "SG_18" or id == "SG_19" or id == "SG_20")) or (type == "fsr" and id.startswith("FSR_STEER"))
108   :show_link_names:
109   :link_types: mitigates,derives_from
110   :scale: 90
111
112Brake System Critical Path
113~~~~~~~~~~~~~~~~~~~~~~~~~~~
114
115Traceability from hazard through brake safety goals to brake FSRs.
116
117.. needflow::
118   :filter: (id == "HAZ_TRAJ_DEV") or (type == "safety_goal" and (id == "SG_15" or id == "SG_16")) or (type == "fsr" and id.startswith("FSR_BRAKE"))
119   :show_link_names:
120   :link_types: mitigates,derives_from
121   :scale: 90
122
123Drive System Critical Path
124~~~~~~~~~~~~~~~~~~~~~~~~~~~
125
126Traceability from hazard through drive safety goals to drive FSRs.
127
128.. needflow::
129   :filter: (id == "HAZ_TRAJ_DEV") or (type == "safety_goal" and (id == "SG_13" or id == "SG_14")) or (type == "fsr" and id.startswith("FSR_DRIVE"))
130   :show_link_names:
131   :link_types: mitigates,derives_from
132   :scale: 90
133
134Safety Goal Coverage
135---------------------
136
137Coverage of Safety Goals by FSRs
138~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
139
140This table shows which FSRs derive from each safety goal, providing visibility
141into requirement decomposition completeness.
142
143.. needtable::
144   :filter: type == "safety_goal" and docname is not None and "safety_example" in docname
145   :columns: id, title, derives_from_back
146   :style: table
147   :colwidths: 15, 45, 40
148
149FSR Completeness Analysis
150--------------------------
151
152FSRs by Category
153~~~~~~~~~~~~~~~~
154
155Controller FSRs
156^^^^^^^^^^^^^^^
157
158.. needtable::
159   :filter: type == "fsr" and docname is not None and "safety_example" in docname and "Controller" in title
160   :columns: id, title, asil, status
161   :style: table
162
163Sensor FSRs
164^^^^^^^^^^^
165
166.. needtable::
167   :filter: type == "fsr" and docname is not None and "safety_example" in docname and "Sensor" in title
168   :columns: id, title, asil, status
169   :style: table
170
171Process FSRs
172^^^^^^^^^^^^
173
174.. needtable::
175   :filter: type == "fsr" and docname is not None and "safety_example" in docname and ("Process" in title or "Component" in title)
176   :columns: id, title, asil, status
177   :style: table
178
179Power Supply FSRs
180^^^^^^^^^^^^^^^^^
181
182.. needtable::
183   :filter: type == "fsr" and docname is not None and "safety_example" in docname and "Power" in title
184   :columns: id, title, asil, status
185   :style: table
186
187FSR Implementation Coverage
188----------------------------
189
190This table shows which System Requirements implement each FSR, providing visibility
191into the decomposition from functional safety requirements to concrete system specifications.
192
193.. needtable::
194   :filter: type == "fsr" and docname is not None and "safety_example" in docname
195   :columns: id, title, implements_back
196   :style: table
197   :colwidths: 15, 45, 40
198
199System Requirements Analysis
200-----------------------------
201
202SYSREQs by Subsystem
203~~~~~~~~~~~~~~~~~~~~
204
205.. needpie:: System Requirements by Subsystem
206   :labels: VDC, WRDC, Steering, Brake, Drive
207
208   type == "sysreq" and docname is not None and "safety_example" in docname and "VDC" in id
209   type == "sysreq" and docname is not None and "safety_example" in docname and "WRDC" in id
210   type == "sysreq" and docname is not None and "safety_example" in docname and "STEER" in id
211   type == "sysreq" and docname is not None and "safety_example" in docname and "BRAKE" in id
212   type == "sysreq" and docname is not None and "safety_example" in docname and "DRIVE" in id
213
214VDC System Requirements
215^^^^^^^^^^^^^^^^^^^^^^^
216
217.. needtable::
218   :filter: type == "sysreq" and docname is not None and "safety_example" in docname and "VDC" in id
219   :columns: id, title, asil, status
220   :style: table
221
222WRDC System Requirements
223^^^^^^^^^^^^^^^^^^^^^^^^
224
225.. needtable::
226   :filter: type == "sysreq" and docname is not None and "safety_example" in docname and "WRDC" in id
227   :columns: id, title, asil, status
228   :style: table
229
230Steering System Requirements
231^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
232
233.. needtable::
234   :filter: type == "sysreq" and docname is not None and "safety_example" in docname and "STEER" in id
235   :columns: id, title, asil, status
236   :style: table
237
238Brake System Requirements
239^^^^^^^^^^^^^^^^^^^^^^^^^^
240
241.. needtable::
242   :filter: type == "sysreq" and docname is not None and "safety_example" in docname and "BRAKE" in id
243   :columns: id, title, asil, status
244   :style: table
245
246Drive System Requirements
247^^^^^^^^^^^^^^^^^^^^^^^^^^
248
249.. needtable::
250   :filter: type == "sysreq" and docname is not None and "safety_example" in docname and "DRIVE" in id
251   :columns: id, title, asil, status
252   :style: table
253
254ASIL D Requirements Summary
255----------------------------
256
257All safety artifacts in this example are assigned ASIL D, the highest automotive
258safety integrity level. This demonstrates the safety-critical nature of vehicle
259actuation systems in automated driving.
260
261**Total Safety Artifacts:**
262
263- **1** Hazard (HAZ_TRAJ_DEV)
264- **20** Safety Goals (SG_01 to SG_20)
265- **30+** Functional Safety Requirements
266- **18** System Requirements
267
268**ISO 26262 Compliance:**
269
270- All hazards have ASIL assignment with rationale
271- All safety goals mitigate identified hazards
272- All FSRs derive from safety goals
273- All SYSREQs implement FSRs with concrete specifications
274- Complete traceability chain maintained (HAZ → SG → FSR → SYSREQ)
275- Schema validation ensures compliance
276
277**STPA-Based Derivation:**
278
279This example demonstrates the STPA (System-Theoretic Process Analysis) methodology
280applied to vehicle actuation systems:
281
2821. **Control Structure Analysis**: Hierarchical control from trajectory input through
283   VDC/WRDC to individual actuators
2842. **Unsafe Control Actions**: Systematic identification of "when required" and
285   "only when required" conditions
2863. **Causal Factor Analysis**: Control loop components (sensors, processes, controllers,
287   actuators) analyzed for failure modes
2884. **Requirement Derivation**: Safety goals and FSRs derived from causal factors
289
290Verification and Validation
291----------------------------
292
293The safety artifacts in this example would typically be verified through:
294
295- **Requirements Review**: Completeness, consistency, correctness
296- **Design Review**: Architectural safety mechanisms, fault tolerance
297- **FMEA/FTA**: Failure modes and fault trees analysis
298- **Hardware-in-the-Loop Testing**: Controller validation with real actuators
299- **Vehicle Testing**: Full system validation on test track
300- **ISO 26262 Audit**: Independent safety assessment
301
302.. seealso::
303
304   **ISO 26262-3:2018** - Concept phase (HARA, safety goals)
305
306   **ISO 26262-4:2018** - Product development at system level (FSRs, system architecture)
307
308   **ISO 26262-6:2018** - Product development at software level
309
310   Research paper: Stolte, Bagschik, Maurer, "Safety Goals and Functional Safety
311   Requirements for Actuation Systems of Automated Vehicles," IEEE ITSC 2016

📊 Safety Traceability Analysis

This page provides comprehensive visualization and analysis of the complete safety artifact traceability chain from hazards through safety goals and functional safety requirements to system requirements.

Complete Safety Traceability

This diagram shows the complete traceability from the top-level hazard through all 20 safety goals, 30+ functional safety requirements, to 18 system requirements.

No needs passed the filters

Safety Artifacts Overview

Complete list of all safety artifacts with key metadata.

ID

Type Name

Title

Asil

Status

FSR_STEER_CTRL_01

Functional Safety Requirement

Steering Controller Robust Control Algorithm

D

open

FSR_STEER_CTRL_02

Functional Safety Requirement

Steering Controller Validated Dynamics Model

D

open

FSR_STEER_CTRL_03

Functional Safety Requirement

Steering Controller Fail-Operational Design

D

open

FSR_STEER_CTRL_04

Functional Safety Requirement

Steering Controller Timing Requirements

D

open

FSR_STEER_SENS_01

Functional Safety Requirement

Steering Sensor Feedback Compensation

D

open

FSR_STEER_SENS_02

Functional Safety Requirement

Steering Sensor Power Supply

D

open

FSR_STEER_SENS_03

Functional Safety Requirement

Steering Sensor Measurement Accuracy

D

open

FSR_STEER_PROC_01

Functional Safety Requirement

Steering Mechanical Design

D

open

FSR_STEER_PROC_02

Functional Safety Requirement

Steering Component Monitoring

D

open

FSR_BRAKE_CTRL_01

Functional Safety Requirement

Brake Controller Robust Algorithm

D

open

FSR_BRAKE_CTRL_02

Functional Safety Requirement

Brake Controller Fail-Operational Design

D

open

FSR_BRAKE_CTRL_03

Functional Safety Requirement

Brake Controller Operational Monitoring

D

open

FSR_BRAKE_PROC_01

Functional Safety Requirement

Brake System Design Limits

D

open

FSR_BRAKE_PROC_02

Functional Safety Requirement

Brake Component Health Monitoring

D

open

FSR_DRIVE_CTRL_01

Functional Safety Requirement

Drive Controller Robust Algorithm

D

open

FSR_DRIVE_CTRL_02

Functional Safety Requirement

Drive Controller Validated Model

D

open

FSR_DRIVE_CTRL_03

Functional Safety Requirement

Drive Controller Fail-Operational Design

D

open

FSR_DRIVE_PROC_01

Functional Safety Requirement

Drive Component Monitoring

D

open

FSR_DRIVE_PROC_02

Functional Safety Requirement

Drive System Design Limits

D

open

FSR_WRDC_CTRL_01

Functional Safety Requirement

WRDC Fault-Tolerant Algorithm

D

open

FSR_WRDC_CTRL_02

Functional Safety Requirement

WRDC Fail-Operational Design

D

open

FSR_WRDC_CTRL_03

Functional Safety Requirement

WRDC Precise Dynamics Model

D

open

FSR_WRDC_CTRL_04

Functional Safety Requirement

WRDC Timing Requirements

D

open

FSR_VDC_CTRL_01

Functional Safety Requirement

VDC Robust Control Algorithm

D

open

FSR_VDC_CTRL_02

Functional Safety Requirement

VDC Validated Dynamics Model

D

open

FSR_VDC_CTRL_03

Functional Safety Requirement

VDC Fail-Operational Design

D

open

FSR_VDC_CTRL_04

Functional Safety Requirement

VDC Fault-Tolerant Algorithm

D

open

FSR_VEHICLE_SENS_01

Functional Safety Requirement

Vehicle Motion Sensor Feedback

D

open

FSR_VEHICLE_SENS_02

Functional Safety Requirement

Vehicle Motion Sensor Accuracy

D

open

FSR_VEHICLE_SENS_03

Functional Safety Requirement

Vehicle Motion Sensor Timing

D

open

FSR_WHEEL_SENS_01

Functional Safety Requirement

Wheel Motion Sensor Compensation

D

open

FSR_WHEEL_SENS_02

Functional Safety Requirement

Wheel Motion Sensor Power

D

open

FSR_PROC_CONFLICT_01

Functional Safety Requirement

Vehicle Dynamics Control Action Consistency

D

open

FSR_PROC_CONFLICT_02

Functional Safety Requirement

Wheel Dynamics Brake-Drive Conflict Prevention

D

open

FSR_POWER_01

Functional Safety Requirement

Actuator Power Supply Continuity

D

open

FSR_POWER_02

Functional Safety Requirement

Controller Power Supply Continuity

D

open

HAZ_TRAJ_DEV

Hazard

Vehicle Not Following Intended Trajectory

D

open

SG_01

Safety Goal

VDC Must Set Target Wheel Torque When Required

D

open

SG_02

Safety Goal

VDC Must Set Target Wheel Torque Only When Required

D

open

SG_03

Safety Goal

VDC Must Set Target Steering Angle When Required

D

open

SG_04

Safety Goal

VDC Must Set Target Steering Angle Only When Required

D

open

SG_05

Safety Goal

WRDC Must Change Target Brake Torque When Required

D

open

SG_06

Safety Goal

WRDC Must Change Target Brake Torque Only When Required

D

open

SG_07

Safety Goal

WRDC Must Change Target Drive Torque When Required

D

open

SG_08

Safety Goal

WRDC Must Change Target Drive Torque Only When Required

D

open

SG_09

Safety Goal

Anti-lock Control Must Be Performed Only When Required

D

open

SG_10

Safety Goal

Anti-lock Control Must Be Performed When Required

D

open

SG_11

Safety Goal

Anti-spin Control Must Be Performed Only When Required

D

open

SG_12

Safety Goal

Anti-spin Control Must Be Performed When Required

D

open

SG_13

Safety Goal

Drive Controller Must Apply Drive Torque When Required

D

open

SG_14

Safety Goal

Drive Controller Must Apply Drive Torque Only When Required

D

open

SG_15

Safety Goal

Brake Controller Must Engage Brake When Required

D

open

SG_16

Safety Goal

Brake Controller Must Engage Brake Only When Required

D

open

SG_17

Safety Goal

SC Must Change Steering Angle When Required

D

open

SG_18

Safety Goal

SC Must Change Steering Angle Only When Required

D

open

SG_19

Safety Goal

SC Must Hold Steering Angle When Required

D

open

SG_20

Safety Goal

SC Must Hold Steering Angle Only When Required

D

open

SYSREQ_VDC_01

System Requirement

VDC Trajectory Tracking Accuracy

D

open

SYSREQ_VDC_02

System Requirement

VDC Dual-Redundant Processing Architecture

D

open

SYSREQ_VDC_03

System Requirement

VDC Multi-Sensor Fusion System

D

open

SYSREQ_VDC_04

System Requirement

VDC Graceful Degradation Controller

D

open

SYSREQ_WRDC_01

System Requirement

WRDC Single Wheel Fault Tolerance

D

open

SYSREQ_WRDC_02

System Requirement

WRDC Tire Friction Estimation System

D

open

SYSREQ_WRDC_03

System Requirement

WRDC ABS/ASR Coordination Logic

D

open

SYSREQ_WRDC_04

System Requirement

WRDC High-Frequency Control Loop

D

open

SYSREQ_STEER_01

System Requirement

Steering Robust Control Algorithm

D

open

SYSREQ_STEER_02

System Requirement

Steering Validated Dynamics Model

D

open

SYSREQ_STEER_03

System Requirement

Steering Redundant Execution Architecture

D

open

SYSREQ_STEER_04

System Requirement

Steering High-Resolution Feedback System

D

open

SYSREQ_BRAKE_01

System Requirement

Brake Dual-Circuit Hydraulic Architecture

D

open

SYSREQ_BRAKE_02

System Requirement

Brake Surface Friction Adaptation

D

open

SYSREQ_BRAKE_03

System Requirement

Brake Component Monitoring System

D

open

SYSREQ_DRIVE_01

System Requirement

Drive Torque Control System

D

open

SYSREQ_DRIVE_02

System Requirement

Drive Limp-Home Mode Architecture

D

open

SYSREQ_DRIVE_03

System Requirement

Drive Electrical and Thermal Protection

D

open

ASIL Distribution Analysis

Distribution of Safety Artifacts by Type

../_images/need_pie_62f17.svg

Safety Goals by Subsystem

../_images/need_pie_01655.svg

FSRs by Subsystem

../_images/need_pie_9d820.svg

Critical Path Analysis

Vehicle Dynamics Controller Critical Path

Traceability from hazard through VDC safety goals to VDC FSRs.

@startuml ' Nodes definition node "<size:12>Functional Safety Requirement</size>\n**VDC Robust**\n**Control**\n**Algorithm**\n<size:10>FSR_VDC_CTRL_01</size>" as FSR_VDC_CTRL_01 [[../safety_example/fsr.html#FSR_VDC_CTRL_01]] #FFD700 node "<size:12>Functional Safety Requirement</size>\n**VDC Validated**\n**Dynamics Model**\n<size:10>FSR_VDC_CTRL_02</size>" as FSR_VDC_CTRL_02 [[../safety_example/fsr.html#FSR_VDC_CTRL_02]] #FFD700 node "<size:12>Functional Safety Requirement</size>\n**VDC Fail-**\n**Operational**\n**Design**\n<size:10>FSR_VDC_CTRL_03</size>" as FSR_VDC_CTRL_03 [[../safety_example/fsr.html#FSR_VDC_CTRL_03]] #FFD700 node "<size:12>Functional Safety Requirement</size>\n**VDC Fault-**\n**Tolerant**\n**Algorithm**\n<size:10>FSR_VDC_CTRL_04</size>" as FSR_VDC_CTRL_04 [[../safety_example/fsr.html#FSR_VDC_CTRL_04]] #FFD700 node "<size:12>Hazard</size>\n**Vehicle Not**\n**Following**\n**Intended**\n**Trajectory**\n<size:10>HAZ_TRAJ_DEV</size>" as HAZ_TRAJ_DEV [[../safety_example/hara.html#HAZ_TRAJ_DEV]] #DC143C node "<size:12>Safety Goal</size>\n**VDC Must Set**\n**Target Wheel**\n**Torque When**\n**Required**\n<size:10>SG_01</size>" as SG_01 [[../safety_example/safety_goals.html#SG_01]] #FF8C00 node "<size:12>Safety Goal</size>\n**VDC Must Set**\n**Target Wheel**\n**Torque Only**\n**When Required**\n<size:10>SG_02</size>" as SG_02 [[../safety_example/safety_goals.html#SG_02]] #FF8C00 node "<size:12>Safety Goal</size>\n**VDC Must Set**\n**Target Steering**\n**Angle When**\n**Required**\n<size:10>SG_03</size>" as SG_03 [[../safety_example/safety_goals.html#SG_03]] #FF8C00 node "<size:12>Safety Goal</size>\n**VDC Must Set**\n**Target Steering**\n**Angle Only When**\n**Required**\n<size:10>SG_04</size>" as SG_04 [[../safety_example/safety_goals.html#SG_04]] #FF8C00 ' Connection definition FSR_VDC_CTRL_01 --> SG_01: derives from\n FSR_VDC_CTRL_01 --> SG_02: derives from\n FSR_VDC_CTRL_01 --> SG_03: derives from\n FSR_VDC_CTRL_01 --> SG_04: derives from\n FSR_VDC_CTRL_02 --> SG_01: derives from\n FSR_VDC_CTRL_02 --> SG_02: derives from\n FSR_VDC_CTRL_02 --> SG_03: derives from\n FSR_VDC_CTRL_02 --> SG_04: derives from\n FSR_VDC_CTRL_03 --> SG_01: derives from\n FSR_VDC_CTRL_03 --> SG_02: derives from\n FSR_VDC_CTRL_03 --> SG_03: derives from\n FSR_VDC_CTRL_03 --> SG_04: derives from\n FSR_VDC_CTRL_04 --> SG_01: derives from\n FSR_VDC_CTRL_04 --> SG_02: derives from\n FSR_VDC_CTRL_04 --> SG_03: derives from\n FSR_VDC_CTRL_04 --> SG_04: derives from\n SG_01 --> HAZ_TRAJ_DEV: mitigates\n SG_02 --> HAZ_TRAJ_DEV: mitigates\n SG_03 --> HAZ_TRAJ_DEV: mitigates\n SG_04 --> HAZ_TRAJ_DEV: mitigates\n @enduml

Wheel Rotational Dynamics Controller Critical Path

Traceability from hazard through WRDC safety goals to WRDC FSRs.

@startuml ' Nodes definition node "<size:12>Functional Safety Requirement</size>\n**WRDC Fault-**\n**Tolerant**\n**Algorithm**\n<size:10>FSR_WRDC_CTRL_01</size>" as FSR_WRDC_CTRL_01 [[../safety_example/fsr.html#FSR_WRDC_CTRL_01]] #FFD700 node "<size:12>Functional Safety Requirement</size>\n**WRDC Fail-**\n**Operational**\n**Design**\n<size:10>FSR_WRDC_CTRL_02</size>" as FSR_WRDC_CTRL_02 [[../safety_example/fsr.html#FSR_WRDC_CTRL_02]] #FFD700 node "<size:12>Functional Safety Requirement</size>\n**WRDC Precise**\n**Dynamics Model**\n<size:10>FSR_WRDC_CTRL_03</size>" as FSR_WRDC_CTRL_03 [[../safety_example/fsr.html#FSR_WRDC_CTRL_03]] #FFD700 node "<size:12>Functional Safety Requirement</size>\n**WRDC Timing**\n**Requirements**\n<size:10>FSR_WRDC_CTRL_04</size>" as FSR_WRDC_CTRL_04 [[../safety_example/fsr.html#FSR_WRDC_CTRL_04]] #FFD700 node "<size:12>Hazard</size>\n**Vehicle Not**\n**Following**\n**Intended**\n**Trajectory**\n<size:10>HAZ_TRAJ_DEV</size>" as HAZ_TRAJ_DEV [[../safety_example/hara.html#HAZ_TRAJ_DEV]] #DC143C node "<size:12>Safety Goal</size>\n**WRDC Must**\n**Change Target**\n**Brake Torque**\n**When Required**\n<size:10>SG_05</size>" as SG_05 [[../safety_example/safety_goals.html#SG_05]] #FF8C00 node "<size:12>Safety Goal</size>\n**WRDC Must**\n**Change Target**\n**Brake Torque**\n**Only When**\n**Required**\n<size:10>SG_06</size>" as SG_06 [[../safety_example/safety_goals.html#SG_06]] #FF8C00 node "<size:12>Safety Goal</size>\n**WRDC Must**\n**Change Target**\n**Drive Torque**\n**When Required**\n<size:10>SG_07</size>" as SG_07 [[../safety_example/safety_goals.html#SG_07]] #FF8C00 node "<size:12>Safety Goal</size>\n**WRDC Must**\n**Change Target**\n**Drive Torque**\n**Only When**\n**Required**\n<size:10>SG_08</size>" as SG_08 [[../safety_example/safety_goals.html#SG_08]] #FF8C00 node "<size:12>Safety Goal</size>\n**Anti-lock**\n**Control Must Be**\n**Performed Only**\n**When Required**\n<size:10>SG_09</size>" as SG_09 [[../safety_example/safety_goals.html#SG_09]] #FF8C00 node "<size:12>Safety Goal</size>\n**Anti-lock**\n**Control Must Be**\n**Performed When**\n**Required**\n<size:10>SG_10</size>" as SG_10 [[../safety_example/safety_goals.html#SG_10]] #FF8C00 node "<size:12>Safety Goal</size>\n**Anti-spin**\n**Control Must Be**\n**Performed Only**\n**When Required**\n<size:10>SG_11</size>" as SG_11 [[../safety_example/safety_goals.html#SG_11]] #FF8C00 node "<size:12>Safety Goal</size>\n**Anti-spin**\n**Control Must Be**\n**Performed When**\n**Required**\n<size:10>SG_12</size>" as SG_12 [[../safety_example/safety_goals.html#SG_12]] #FF8C00 ' Connection definition FSR_WRDC_CTRL_01 --> SG_05: derives from\n FSR_WRDC_CTRL_01 --> SG_06: derives from\n FSR_WRDC_CTRL_01 --> SG_07: derives from\n FSR_WRDC_CTRL_01 --> SG_08: derives from\n FSR_WRDC_CTRL_01 --> SG_09: derives from\n FSR_WRDC_CTRL_01 --> SG_10: derives from\n FSR_WRDC_CTRL_01 --> SG_11: derives from\n FSR_WRDC_CTRL_01 --> SG_12: derives from\n FSR_WRDC_CTRL_02 --> SG_05: derives from\n FSR_WRDC_CTRL_02 --> SG_06: derives from\n FSR_WRDC_CTRL_02 --> SG_07: derives from\n FSR_WRDC_CTRL_02 --> SG_08: derives from\n FSR_WRDC_CTRL_02 --> SG_09: derives from\n FSR_WRDC_CTRL_02 --> SG_10: derives from\n FSR_WRDC_CTRL_02 --> SG_11: derives from\n FSR_WRDC_CTRL_02 --> SG_12: derives from\n FSR_WRDC_CTRL_03 --> SG_05: derives from\n FSR_WRDC_CTRL_03 --> SG_06: derives from\n FSR_WRDC_CTRL_03 --> SG_07: derives from\n FSR_WRDC_CTRL_03 --> SG_08: derives from\n FSR_WRDC_CTRL_03 --> SG_09: derives from\n FSR_WRDC_CTRL_03 --> SG_10: derives from\n FSR_WRDC_CTRL_03 --> SG_11: derives from\n FSR_WRDC_CTRL_03 --> SG_12: derives from\n FSR_WRDC_CTRL_04 --> SG_05: derives from\n FSR_WRDC_CTRL_04 --> SG_06: derives from\n FSR_WRDC_CTRL_04 --> SG_07: derives from\n FSR_WRDC_CTRL_04 --> SG_08: derives from\n FSR_WRDC_CTRL_04 --> SG_09: derives from\n FSR_WRDC_CTRL_04 --> SG_10: derives from\n FSR_WRDC_CTRL_04 --> SG_11: derives from\n FSR_WRDC_CTRL_04 --> SG_12: derives from\n SG_05 --> HAZ_TRAJ_DEV: mitigates\n SG_06 --> HAZ_TRAJ_DEV: mitigates\n SG_07 --> HAZ_TRAJ_DEV: mitigates\n SG_08 --> HAZ_TRAJ_DEV: mitigates\n SG_09 --> HAZ_TRAJ_DEV: mitigates\n SG_10 --> HAZ_TRAJ_DEV: mitigates\n SG_11 --> HAZ_TRAJ_DEV: mitigates\n SG_12 --> HAZ_TRAJ_DEV: mitigates\n @enduml

Steering System Critical Path

Traceability from hazard through steering safety goals to steering FSRs.

@startuml ' Nodes definition node "<size:12>Functional Safety Requirement</size>\n**Steering**\n**Controller**\n**Robust Control**\n**Algorithm**\n<size:10>FSR_STEER_CTRL_01</size>" as FSR_STEER_CTRL_01 [[../safety_example/fsr.html#FSR_STEER_CTRL_01]] #FFD700 node "<size:12>Functional Safety Requirement</size>\n**Steering**\n**Controller**\n**Validated**\n**Dynamics Model**\n<size:10>FSR_STEER_CTRL_02</size>" as FSR_STEER_CTRL_02 [[../safety_example/fsr.html#FSR_STEER_CTRL_02]] #FFD700 node "<size:12>Functional Safety Requirement</size>\n**Steering**\n**Controller**\n**Fail-**\n**Operational**\n**Design**\n<size:10>FSR_STEER_CTRL_03</size>" as FSR_STEER_CTRL_03 [[../safety_example/fsr.html#FSR_STEER_CTRL_03]] #FFD700 node "<size:12>Functional Safety Requirement</size>\n**Steering**\n**Controller**\n**Timing**\n**Requirements**\n<size:10>FSR_STEER_CTRL_04</size>" as FSR_STEER_CTRL_04 [[../safety_example/fsr.html#FSR_STEER_CTRL_04]] #FFD700 node "<size:12>Functional Safety Requirement</size>\n**Steering Sensor**\n**Feedback**\n**Compensation**\n<size:10>FSR_STEER_SENS_01</size>" as FSR_STEER_SENS_01 [[../safety_example/fsr.html#FSR_STEER_SENS_01]] #FFD700 node "<size:12>Functional Safety Requirement</size>\n**Steering Sensor**\n**Power Supply**\n<size:10>FSR_STEER_SENS_02</size>" as FSR_STEER_SENS_02 [[../safety_example/fsr.html#FSR_STEER_SENS_02]] #FFD700 node "<size:12>Functional Safety Requirement</size>\n**Steering Sensor**\n**Measurement**\n**Accuracy**\n<size:10>FSR_STEER_SENS_03</size>" as FSR_STEER_SENS_03 [[../safety_example/fsr.html#FSR_STEER_SENS_03]] #FFD700 node "<size:12>Functional Safety Requirement</size>\n**Steering**\n**Mechanical**\n**Design**\n<size:10>FSR_STEER_PROC_01</size>" as FSR_STEER_PROC_01 [[../safety_example/fsr.html#FSR_STEER_PROC_01]] #FFD700 node "<size:12>Functional Safety Requirement</size>\n**Steering**\n**Component**\n**Monitoring**\n<size:10>FSR_STEER_PROC_02</size>" as FSR_STEER_PROC_02 [[../safety_example/fsr.html#FSR_STEER_PROC_02]] #FFD700 node "<size:12>Hazard</size>\n**Vehicle Not**\n**Following**\n**Intended**\n**Trajectory**\n<size:10>HAZ_TRAJ_DEV</size>" as HAZ_TRAJ_DEV [[../safety_example/hara.html#HAZ_TRAJ_DEV]] #DC143C node "<size:12>Safety Goal</size>\n**SC Must Change**\n**Steering Angle**\n**When Required**\n<size:10>SG_17</size>" as SG_17 [[../safety_example/safety_goals.html#SG_17]] #FF8C00 node "<size:12>Safety Goal</size>\n**SC Must Change**\n**Steering Angle**\n**Only When**\n**Required**\n<size:10>SG_18</size>" as SG_18 [[../safety_example/safety_goals.html#SG_18]] #FF8C00 node "<size:12>Safety Goal</size>\n**SC Must Hold**\n**Steering Angle**\n**When Required**\n<size:10>SG_19</size>" as SG_19 [[../safety_example/safety_goals.html#SG_19]] #FF8C00 node "<size:12>Safety Goal</size>\n**SC Must Hold**\n**Steering Angle**\n**Only When**\n**Required**\n<size:10>SG_20</size>" as SG_20 [[../safety_example/safety_goals.html#SG_20]] #FF8C00 ' Connection definition FSR_STEER_CTRL_01 --> SG_17: derives from\n FSR_STEER_CTRL_01 --> SG_18: derives from\n FSR_STEER_CTRL_01 --> SG_19: derives from\n FSR_STEER_CTRL_01 --> SG_20: derives from\n FSR_STEER_CTRL_02 --> SG_17: derives from\n FSR_STEER_CTRL_02 --> SG_18: derives from\n FSR_STEER_CTRL_02 --> SG_19: derives from\n FSR_STEER_CTRL_02 --> SG_20: derives from\n FSR_STEER_CTRL_03 --> SG_17: derives from\n FSR_STEER_CTRL_03 --> SG_18: derives from\n FSR_STEER_CTRL_03 --> SG_19: derives from\n FSR_STEER_CTRL_03 --> SG_20: derives from\n FSR_STEER_CTRL_04 --> SG_17: derives from\n FSR_STEER_CTRL_04 --> SG_18: derives from\n FSR_STEER_CTRL_04 --> SG_19: derives from\n FSR_STEER_CTRL_04 --> SG_20: derives from\n FSR_STEER_SENS_01 --> SG_17: derives from\n FSR_STEER_SENS_01 --> SG_18: derives from\n FSR_STEER_SENS_01 --> SG_19: derives from\n FSR_STEER_SENS_01 --> SG_20: derives from\n FSR_STEER_SENS_02 --> SG_17: derives from\n FSR_STEER_SENS_02 --> SG_18: derives from\n FSR_STEER_SENS_02 --> SG_19: derives from\n FSR_STEER_SENS_02 --> SG_20: derives from\n FSR_STEER_SENS_03 --> SG_17: derives from\n FSR_STEER_SENS_03 --> SG_18: derives from\n FSR_STEER_SENS_03 --> SG_19: derives from\n FSR_STEER_SENS_03 --> SG_20: derives from\n FSR_STEER_PROC_01 --> SG_17: derives from\n FSR_STEER_PROC_01 --> SG_18: derives from\n FSR_STEER_PROC_01 --> SG_19: derives from\n FSR_STEER_PROC_01 --> SG_20: derives from\n FSR_STEER_PROC_02 --> SG_17: derives from\n FSR_STEER_PROC_02 --> SG_18: derives from\n FSR_STEER_PROC_02 --> SG_19: derives from\n FSR_STEER_PROC_02 --> SG_20: derives from\n SG_17 --> HAZ_TRAJ_DEV: mitigates\n SG_18 --> HAZ_TRAJ_DEV: mitigates\n SG_19 --> HAZ_TRAJ_DEV: mitigates\n SG_20 --> HAZ_TRAJ_DEV: mitigates\n @enduml

Brake System Critical Path

Traceability from hazard through brake safety goals to brake FSRs.

@startuml ' Nodes definition node "<size:12>Functional Safety Requirement</size>\n**Brake**\n**Controller**\n**Robust**\n**Algorithm**\n<size:10>FSR_BRAKE_CTRL_01</size>" as FSR_BRAKE_CTRL_01 [[../safety_example/fsr.html#FSR_BRAKE_CTRL_01]] #FFD700 node "<size:12>Functional Safety Requirement</size>\n**Brake**\n**Controller**\n**Fail-**\n**Operational**\n**Design**\n<size:10>FSR_BRAKE_CTRL_02</size>" as FSR_BRAKE_CTRL_02 [[../safety_example/fsr.html#FSR_BRAKE_CTRL_02]] #FFD700 node "<size:12>Functional Safety Requirement</size>\n**Brake**\n**Controller**\n**Operational**\n**Monitoring**\n<size:10>FSR_BRAKE_CTRL_03</size>" as FSR_BRAKE_CTRL_03 [[../safety_example/fsr.html#FSR_BRAKE_CTRL_03]] #FFD700 node "<size:12>Functional Safety Requirement</size>\n**Brake System**\n**Design Limits**\n<size:10>FSR_BRAKE_PROC_01</size>" as FSR_BRAKE_PROC_01 [[../safety_example/fsr.html#FSR_BRAKE_PROC_01]] #FFD700 node "<size:12>Functional Safety Requirement</size>\n**Brake Component**\n**Health**\n**Monitoring**\n<size:10>FSR_BRAKE_PROC_02</size>" as FSR_BRAKE_PROC_02 [[../safety_example/fsr.html#FSR_BRAKE_PROC_02]] #FFD700 node "<size:12>Hazard</size>\n**Vehicle Not**\n**Following**\n**Intended**\n**Trajectory**\n<size:10>HAZ_TRAJ_DEV</size>" as HAZ_TRAJ_DEV [[../safety_example/hara.html#HAZ_TRAJ_DEV]] #DC143C node "<size:12>Safety Goal</size>\n**Brake**\n**Controller Must**\n**Engage Brake**\n**When Required**\n<size:10>SG_15</size>" as SG_15 [[../safety_example/safety_goals.html#SG_15]] #FF8C00 node "<size:12>Safety Goal</size>\n**Brake**\n**Controller Must**\n**Engage Brake**\n**Only When**\n**Required**\n<size:10>SG_16</size>" as SG_16 [[../safety_example/safety_goals.html#SG_16]] #FF8C00 ' Connection definition FSR_BRAKE_CTRL_01 --> SG_15: derives from\n FSR_BRAKE_CTRL_01 --> SG_16: derives from\n FSR_BRAKE_CTRL_02 --> SG_15: derives from\n FSR_BRAKE_CTRL_02 --> SG_16: derives from\n FSR_BRAKE_CTRL_03 --> SG_15: derives from\n FSR_BRAKE_CTRL_03 --> SG_16: derives from\n FSR_BRAKE_PROC_01 --> SG_15: derives from\n FSR_BRAKE_PROC_01 --> SG_16: derives from\n FSR_BRAKE_PROC_02 --> SG_15: derives from\n FSR_BRAKE_PROC_02 --> SG_16: derives from\n SG_15 --> HAZ_TRAJ_DEV: mitigates\n SG_16 --> HAZ_TRAJ_DEV: mitigates\n @enduml

Drive System Critical Path

Traceability from hazard through drive safety goals to drive FSRs.

@startuml ' Nodes definition node "<size:12>Functional Safety Requirement</size>\n**Drive**\n**Controller**\n**Robust**\n**Algorithm**\n<size:10>FSR_DRIVE_CTRL_01</size>" as FSR_DRIVE_CTRL_01 [[../safety_example/fsr.html#FSR_DRIVE_CTRL_01]] #FFD700 node "<size:12>Functional Safety Requirement</size>\n**Drive**\n**Controller**\n**Validated Model**\n<size:10>FSR_DRIVE_CTRL_02</size>" as FSR_DRIVE_CTRL_02 [[../safety_example/fsr.html#FSR_DRIVE_CTRL_02]] #FFD700 node "<size:12>Functional Safety Requirement</size>\n**Drive**\n**Controller**\n**Fail-**\n**Operational**\n**Design**\n<size:10>FSR_DRIVE_CTRL_03</size>" as FSR_DRIVE_CTRL_03 [[../safety_example/fsr.html#FSR_DRIVE_CTRL_03]] #FFD700 node "<size:12>Functional Safety Requirement</size>\n**Drive Component**\n**Monitoring**\n<size:10>FSR_DRIVE_PROC_01</size>" as FSR_DRIVE_PROC_01 [[../safety_example/fsr.html#FSR_DRIVE_PROC_01]] #FFD700 node "<size:12>Functional Safety Requirement</size>\n**Drive System**\n**Design Limits**\n<size:10>FSR_DRIVE_PROC_02</size>" as FSR_DRIVE_PROC_02 [[../safety_example/fsr.html#FSR_DRIVE_PROC_02]] #FFD700 node "<size:12>Hazard</size>\n**Vehicle Not**\n**Following**\n**Intended**\n**Trajectory**\n<size:10>HAZ_TRAJ_DEV</size>" as HAZ_TRAJ_DEV [[../safety_example/hara.html#HAZ_TRAJ_DEV]] #DC143C node "<size:12>Safety Goal</size>\n**Drive**\n**Controller Must**\n**Apply Drive**\n**Torque When**\n**Required**\n<size:10>SG_13</size>" as SG_13 [[../safety_example/safety_goals.html#SG_13]] #FF8C00 node "<size:12>Safety Goal</size>\n**Drive**\n**Controller Must**\n**Apply Drive**\n**Torque Only**\n**When Required**\n<size:10>SG_14</size>" as SG_14 [[../safety_example/safety_goals.html#SG_14]] #FF8C00 ' Connection definition FSR_DRIVE_CTRL_01 --> SG_13: derives from\n FSR_DRIVE_CTRL_01 --> SG_14: derives from\n FSR_DRIVE_CTRL_02 --> SG_13: derives from\n FSR_DRIVE_CTRL_02 --> SG_14: derives from\n FSR_DRIVE_CTRL_03 --> SG_13: derives from\n FSR_DRIVE_CTRL_03 --> SG_14: derives from\n FSR_DRIVE_PROC_01 --> SG_13: derives from\n FSR_DRIVE_PROC_01 --> SG_14: derives from\n FSR_DRIVE_PROC_02 --> SG_13: derives from\n FSR_DRIVE_PROC_02 --> SG_14: derives from\n SG_13 --> HAZ_TRAJ_DEV: mitigates\n SG_14 --> HAZ_TRAJ_DEV: mitigates\n @enduml

Safety Goal Coverage

Coverage of Safety Goals by FSRs

This table shows which FSRs derive from each safety goal, providing visibility into requirement decomposition completeness.

ID

Title

Derives From Back

SG_01

VDC Must Set Target Wheel Torque When Required

FSR_VDC_CTRL_01; FSR_VDC_CTRL_02; FSR_VDC_CTRL_03; FSR_VDC_CTRL_04; FSR_VEHICLE_SENS_01; FSR_VEHICLE_SENS_02; FSR_VEHICLE_SENS_03; FSR_PROC_CONFLICT_01; FSR_POWER_02

SG_02

VDC Must Set Target Wheel Torque Only When Required

FSR_VDC_CTRL_01; FSR_VDC_CTRL_02; FSR_VDC_CTRL_03; FSR_VDC_CTRL_04; FSR_VEHICLE_SENS_01; FSR_VEHICLE_SENS_02; FSR_VEHICLE_SENS_03; FSR_PROC_CONFLICT_01; FSR_POWER_02

SG_03

VDC Must Set Target Steering Angle When Required

FSR_VDC_CTRL_01; FSR_VDC_CTRL_02; FSR_VDC_CTRL_03; FSR_VDC_CTRL_04; FSR_VEHICLE_SENS_01; FSR_VEHICLE_SENS_02; FSR_VEHICLE_SENS_03; FSR_PROC_CONFLICT_01; FSR_POWER_02

SG_04

VDC Must Set Target Steering Angle Only When Required

FSR_VDC_CTRL_01; FSR_VDC_CTRL_02; FSR_VDC_CTRL_03; FSR_VDC_CTRL_04; FSR_VEHICLE_SENS_01; FSR_VEHICLE_SENS_02; FSR_VEHICLE_SENS_03; FSR_PROC_CONFLICT_01; FSR_POWER_02

SG_05

WRDC Must Change Target Brake Torque When Required

FSR_BRAKE_PROC_01; FSR_WRDC_CTRL_01; FSR_WRDC_CTRL_02; FSR_WRDC_CTRL_03; FSR_WRDC_CTRL_04; FSR_PROC_CONFLICT_02; FSR_POWER_02

SG_06

WRDC Must Change Target Brake Torque Only When Required

FSR_BRAKE_PROC_01; FSR_WRDC_CTRL_01; FSR_WRDC_CTRL_02; FSR_WRDC_CTRL_03; FSR_WRDC_CTRL_04; FSR_PROC_CONFLICT_02; FSR_POWER_02

SG_07

WRDC Must Change Target Drive Torque When Required

FSR_DRIVE_PROC_01; FSR_WRDC_CTRL_01; FSR_WRDC_CTRL_02; FSR_WRDC_CTRL_03; FSR_WRDC_CTRL_04; FSR_PROC_CONFLICT_02; FSR_POWER_02

SG_08

WRDC Must Change Target Drive Torque Only When Required

FSR_DRIVE_PROC_01; FSR_WRDC_CTRL_01; FSR_WRDC_CTRL_02; FSR_WRDC_CTRL_03; FSR_WRDC_CTRL_04; FSR_PROC_CONFLICT_02; FSR_POWER_02

SG_09

Anti-lock Control Must Be Performed Only When Required

FSR_WRDC_CTRL_01; FSR_WRDC_CTRL_02; FSR_WRDC_CTRL_03; FSR_WRDC_CTRL_04; FSR_WHEEL_SENS_01; FSR_WHEEL_SENS_02

SG_10

Anti-lock Control Must Be Performed When Required

FSR_WRDC_CTRL_01; FSR_WRDC_CTRL_02; FSR_WRDC_CTRL_03; FSR_WRDC_CTRL_04; FSR_WHEEL_SENS_01; FSR_WHEEL_SENS_02

SG_11

Anti-spin Control Must Be Performed Only When Required

FSR_WRDC_CTRL_01; FSR_WRDC_CTRL_02; FSR_WRDC_CTRL_03; FSR_WRDC_CTRL_04; FSR_WHEEL_SENS_01; FSR_WHEEL_SENS_02

SG_12

Anti-spin Control Must Be Performed When Required

FSR_WRDC_CTRL_01; FSR_WRDC_CTRL_02; FSR_WRDC_CTRL_03; FSR_WRDC_CTRL_04; FSR_WHEEL_SENS_01; FSR_WHEEL_SENS_02

SG_13

Drive Controller Must Apply Drive Torque When Required

FSR_DRIVE_CTRL_01; FSR_DRIVE_CTRL_02; FSR_DRIVE_CTRL_03; FSR_DRIVE_PROC_01; FSR_DRIVE_PROC_02; FSR_POWER_01

SG_14

Drive Controller Must Apply Drive Torque Only When Required

FSR_DRIVE_CTRL_01; FSR_DRIVE_CTRL_02; FSR_DRIVE_CTRL_03; FSR_DRIVE_PROC_01; FSR_DRIVE_PROC_02; FSR_POWER_01

SG_15

Brake Controller Must Engage Brake When Required

FSR_BRAKE_CTRL_01; FSR_BRAKE_CTRL_02; FSR_BRAKE_CTRL_03; FSR_BRAKE_PROC_01; FSR_BRAKE_PROC_02; FSR_POWER_01

SG_16

Brake Controller Must Engage Brake Only When Required

FSR_BRAKE_CTRL_01; FSR_BRAKE_CTRL_02; FSR_BRAKE_CTRL_03; FSR_BRAKE_PROC_01; FSR_BRAKE_PROC_02; FSR_POWER_01

SG_17

SC Must Change Steering Angle When Required

FSR_STEER_CTRL_01; FSR_STEER_CTRL_02; FSR_STEER_CTRL_03; FSR_STEER_CTRL_04; FSR_STEER_SENS_01; FSR_STEER_SENS_02; FSR_STEER_SENS_03; FSR_STEER_PROC_01; FSR_STEER_PROC_02; FSR_POWER_01

SG_18

SC Must Change Steering Angle Only When Required

FSR_STEER_CTRL_01; FSR_STEER_CTRL_02; FSR_STEER_CTRL_03; FSR_STEER_CTRL_04; FSR_STEER_SENS_01; FSR_STEER_SENS_02; FSR_STEER_SENS_03; FSR_STEER_PROC_01; FSR_STEER_PROC_02; FSR_POWER_01

SG_19

SC Must Hold Steering Angle When Required

FSR_STEER_CTRL_01; FSR_STEER_CTRL_02; FSR_STEER_CTRL_03; FSR_STEER_CTRL_04; FSR_STEER_SENS_01; FSR_STEER_SENS_02; FSR_STEER_SENS_03; FSR_STEER_PROC_01; FSR_STEER_PROC_02; FSR_POWER_01

SG_20

SC Must Hold Steering Angle Only When Required

FSR_STEER_CTRL_01; FSR_STEER_CTRL_02; FSR_STEER_CTRL_03; FSR_STEER_CTRL_04; FSR_STEER_SENS_01; FSR_STEER_SENS_02; FSR_STEER_SENS_03; FSR_STEER_PROC_01; FSR_STEER_PROC_02; FSR_POWER_01

FSR Completeness Analysis

FSRs by Category

Controller FSRs

ID

Title

Asil

Status

FSR_BRAKE_CTRL_01

Brake Controller Robust Algorithm

D

open

FSR_BRAKE_CTRL_02

Brake Controller Fail-Operational Design

D

open

FSR_BRAKE_CTRL_03

Brake Controller Operational Monitoring

D

open

FSR_DRIVE_CTRL_01

Drive Controller Robust Algorithm

D

open

FSR_DRIVE_CTRL_02

Drive Controller Validated Model

D

open

FSR_DRIVE_CTRL_03

Drive Controller Fail-Operational Design

D

open

FSR_POWER_02

Controller Power Supply Continuity

D

open

FSR_STEER_CTRL_01

Steering Controller Robust Control Algorithm

D

open

FSR_STEER_CTRL_02

Steering Controller Validated Dynamics Model

D

open

FSR_STEER_CTRL_03

Steering Controller Fail-Operational Design

D

open

FSR_STEER_CTRL_04

Steering Controller Timing Requirements

D

open

Sensor FSRs

ID

Title

Asil

Status

FSR_STEER_SENS_01

Steering Sensor Feedback Compensation

D

open

FSR_STEER_SENS_02

Steering Sensor Power Supply

D

open

FSR_STEER_SENS_03

Steering Sensor Measurement Accuracy

D

open

FSR_VEHICLE_SENS_01

Vehicle Motion Sensor Feedback

D

open

FSR_VEHICLE_SENS_02

Vehicle Motion Sensor Accuracy

D

open

FSR_VEHICLE_SENS_03

Vehicle Motion Sensor Timing

D

open

FSR_WHEEL_SENS_01

Wheel Motion Sensor Compensation

D

open

FSR_WHEEL_SENS_02

Wheel Motion Sensor Power

D

open

Process FSRs

ID

Title

Asil

Status

FSR_BRAKE_PROC_02

Brake Component Health Monitoring

D

open

FSR_DRIVE_PROC_01

Drive Component Monitoring

D

open

FSR_STEER_PROC_02

Steering Component Monitoring

D

open

Power Supply FSRs

ID

Title

Asil

Status

FSR_POWER_01

Actuator Power Supply Continuity

D

open

FSR_POWER_02

Controller Power Supply Continuity

D

open

FSR_STEER_SENS_02

Steering Sensor Power Supply

D

open

FSR_WHEEL_SENS_02

Wheel Motion Sensor Power

D

open

FSR Implementation Coverage

This table shows which System Requirements implement each FSR, providing visibility into the decomposition from functional safety requirements to concrete system specifications.

ID

Title

Implements Back

FSR_BRAKE_CTRL_01

Brake Controller Robust Algorithm

SYSREQ_BRAKE_02

FSR_BRAKE_CTRL_02

Brake Controller Fail-Operational Design

SYSREQ_BRAKE_01

FSR_BRAKE_CTRL_03

Brake Controller Operational Monitoring

FSR_BRAKE_PROC_01

Brake System Design Limits

FSR_BRAKE_PROC_02

Brake Component Health Monitoring

SYSREQ_BRAKE_03

FSR_DRIVE_CTRL_01

Drive Controller Robust Algorithm

SYSREQ_DRIVE_01

FSR_DRIVE_CTRL_02

Drive Controller Validated Model

FSR_DRIVE_CTRL_03

Drive Controller Fail-Operational Design

SYSREQ_DRIVE_02

FSR_DRIVE_PROC_01

Drive Component Monitoring

FSR_DRIVE_PROC_02

Drive System Design Limits

SYSREQ_DRIVE_03

FSR_POWER_01

Actuator Power Supply Continuity

FSR_POWER_02

Controller Power Supply Continuity

FSR_PROC_CONFLICT_01

Vehicle Dynamics Control Action Consistency

FSR_PROC_CONFLICT_02

Wheel Dynamics Brake-Drive Conflict Prevention

FSR_STEER_CTRL_01

Steering Controller Robust Control Algorithm

SYSREQ_STEER_01

FSR_STEER_CTRL_02

Steering Controller Validated Dynamics Model

SYSREQ_STEER_02

FSR_STEER_CTRL_03

Steering Controller Fail-Operational Design

SYSREQ_STEER_03

FSR_STEER_CTRL_04

Steering Controller Timing Requirements

FSR_STEER_PROC_01

Steering Mechanical Design

FSR_STEER_PROC_02

Steering Component Monitoring

FSR_STEER_SENS_01

Steering Sensor Feedback Compensation

FSR_STEER_SENS_02

Steering Sensor Power Supply

FSR_STEER_SENS_03

Steering Sensor Measurement Accuracy

SYSREQ_STEER_04

FSR_VDC_CTRL_01

VDC Robust Control Algorithm

SYSREQ_VDC_01

FSR_VDC_CTRL_02

VDC Validated Dynamics Model

FSR_VDC_CTRL_03

VDC Fail-Operational Design

SYSREQ_VDC_02

FSR_VDC_CTRL_04

VDC Fault-Tolerant Algorithm

SYSREQ_VDC_04

FSR_VEHICLE_SENS_01

Vehicle Motion Sensor Feedback

SYSREQ_VDC_03

FSR_VEHICLE_SENS_02

Vehicle Motion Sensor Accuracy

SYSREQ_VDC_03

FSR_VEHICLE_SENS_03

Vehicle Motion Sensor Timing

FSR_WHEEL_SENS_01

Wheel Motion Sensor Compensation

FSR_WHEEL_SENS_02

Wheel Motion Sensor Power

FSR_WRDC_CTRL_01

WRDC Fault-Tolerant Algorithm

SYSREQ_WRDC_01; SYSREQ_WRDC_03

FSR_WRDC_CTRL_02

WRDC Fail-Operational Design

FSR_WRDC_CTRL_03

WRDC Precise Dynamics Model

SYSREQ_WRDC_02

FSR_WRDC_CTRL_04

WRDC Timing Requirements

SYSREQ_WRDC_04

System Requirements Analysis

SYSREQs by Subsystem

../_images/need_pie_0f66a.svg

VDC System Requirements

ID

Title

Asil

Status

SYSREQ_VDC_01

VDC Trajectory Tracking Accuracy

D

open

SYSREQ_VDC_02

VDC Dual-Redundant Processing Architecture

D

open

SYSREQ_VDC_03

VDC Multi-Sensor Fusion System

D

open

SYSREQ_VDC_04

VDC Graceful Degradation Controller

D

open

WRDC System Requirements

ID

Title

Asil

Status

SYSREQ_WRDC_01

WRDC Single Wheel Fault Tolerance

D

open

SYSREQ_WRDC_02

WRDC Tire Friction Estimation System

D

open

SYSREQ_WRDC_03

WRDC ABS/ASR Coordination Logic

D

open

SYSREQ_WRDC_04

WRDC High-Frequency Control Loop

D

open

Steering System Requirements

ID

Title

Asil

Status

SYSREQ_STEER_01

Steering Robust Control Algorithm

D

open

SYSREQ_STEER_02

Steering Validated Dynamics Model

D

open

SYSREQ_STEER_03

Steering Redundant Execution Architecture

D

open

SYSREQ_STEER_04

Steering High-Resolution Feedback System

D

open

Brake System Requirements

ID

Title

Asil

Status

SYSREQ_BRAKE_01

Brake Dual-Circuit Hydraulic Architecture

D

open

SYSREQ_BRAKE_02

Brake Surface Friction Adaptation

D

open

SYSREQ_BRAKE_03

Brake Component Monitoring System

D

open

Drive System Requirements

ID

Title

Asil

Status

SYSREQ_DRIVE_01

Drive Torque Control System

D

open

SYSREQ_DRIVE_02

Drive Limp-Home Mode Architecture

D

open

SYSREQ_DRIVE_03

Drive Electrical and Thermal Protection

D

open

ASIL D Requirements Summary

All safety artifacts in this example are assigned ASIL D, the highest automotive safety integrity level. This demonstrates the safety-critical nature of vehicle actuation systems in automated driving.

Total Safety Artifacts:

  • 1 Hazard (HAZ_TRAJ_DEV)

  • 20 Safety Goals (SG_01 to SG_20)

  • 30+ Functional Safety Requirements

  • 18 System Requirements

ISO 26262 Compliance:

  • All hazards have ASIL assignment with rationale

  • All safety goals mitigate identified hazards

  • All FSRs derive from safety goals

  • All SYSREQs implement FSRs with concrete specifications

  • Complete traceability chain maintained (HAZ → SG → FSR → SYSREQ)

  • Schema validation ensures compliance

STPA-Based Derivation:

This example demonstrates the STPA (System-Theoretic Process Analysis) methodology applied to vehicle actuation systems:

  1. Control Structure Analysis: Hierarchical control from trajectory input through VDC/WRDC to individual actuators

  2. Unsafe Control Actions: Systematic identification of “when required” and “only when required” conditions

  3. Causal Factor Analysis: Control loop components (sensors, processes, controllers, actuators) analyzed for failure modes

  4. Requirement Derivation: Safety goals and FSRs derived from causal factors

Verification and Validation

The safety artifacts in this example would typically be verified through:

  • Requirements Review: Completeness, consistency, correctness

  • Design Review: Architectural safety mechanisms, fault tolerance

  • FMEA/FTA: Failure modes and fault trees analysis

  • Hardware-in-the-Loop Testing: Controller validation with real actuators

  • Vehicle Testing: Full system validation on test track

  • ISO 26262 Audit: Independent safety assessment

See also

ISO 26262-3:2018 - Concept phase (HARA, safety goals)

ISO 26262-4:2018 - Product development at system level (FSRs, system architecture)

ISO 26262-6:2018 - Product development at software level

Research paper: Stolte, Bagschik, Maurer, “Safety Goals and Functional Safety Requirements for Actuation Systems of Automated Vehicles,” IEEE ITSC 2016