ISO 26262:2018 - Automotive Functional Safety Engineer Free Practice Test — 30 Questions

Question 1

Consider a complex automotive system requiring an ASIL C safety goal for its braking actuation subsystem. The development team decides to decompose this safety goal into two independent hardware components. What is the most appropriate ASIL assignment for each of these decomposed hardware components to maintain the overall safety integrity of the original ASIL C safety goal, adhering to the principles of ASIL decomposition as defined in ISO 26262:2018?

Accepted Answer

ASIL B for each of the two decomposed hardware components

Question 2

Consider a vehicle equipped with an electronic throttle control system. During the hazard analysis and risk assessment (HARA), a critical hazard identified is unintended acceleration caused by a failure in the throttle actuator, leading to a potential for loss of vehicle control. The resulting safety goal is to prevent severe injuries or fatalities resulting from such an event. Which of the following statements best represents a functional safety requirement derived from this safety goal?

Accepted Answer

The system shall detect and mitigate unintended throttle opening above a predefined threshold within $100$ ms.

Question 3

Consider a complex automotive system where a critical safety goal has been assigned an ASIL C. Through a rigorous hazard analysis and risk assessment, the system architect decides to decompose this ASIL C safety goal into two independent elements, each assigned an ASIL B. What is the expected nature of the safety requirements that should be derived for these two decomposed elements to ensure the overall safety integrity of the original ASIL C goal is maintained?

Accepted Answer

Safety requirements derived for each element should correspond to ASIL B, with appropriate safety mechanisms ensuring the combined effect meets the original ASIL C.

Question 4

Consider a vehicle\'s electronic stability control (ESC) system, where a critical function responsible for yaw rate control has been assigned an Automotive Safety Integrity Level (ASIL) C. Due to architectural constraints and the desire for increased fault tolerance, a decision is made to decompose this ASIL C safety goal into two independent hardware elements: Element X, assigned ASIL B, and Element Y, assigned ASIL A. What is the most accurate description of the safety goal for Element X following this decomposition?

Accepted Answer

A safety goal that contributes to achieving the original ASIL C safety goal, derived from the ASIL C safety requirements.

Question 5

Consider a complex automotive system where a critical safety goal has been assigned an ASIL D rating. During the system design phase, this safety goal is decomposed into several lower-level safety requirements allocated to different hardware and software components. What is the most appropriate ASIL assignment for these decomposed hardware and software safety requirements to ensure the overall integrity of the safety goal is maintained, according to ISO 26262:2018 principles?

Accepted Answer

The decomposed hardware and software safety requirements should also be assigned ASIL D.

Question 6

Consider a vehicle\'s electronic stability control (ESC) system. A hazard analysis has identified a potential hazard: \"Loss of vehicle directional control due to abrupt, uncommanded steering actuation.\" This hazard has been assigned an Automotive Safety Integrity Level (ASIL) of C. A safety goal derived from this hazard is: \"Prevent loss of directional control during normal driving maneuvers.\" Which of the following statements accurately describes a requirement that would directly support achieving this safety goal by specifying a safety function?

Accepted Answer

The ESC control unit shall monitor the yaw rate sensor and steering angle sensor for signal plausibility deviations exceeding $5\%$ within $50$ ms and, upon detection, limit the ESC intervention torque to $0$ Nm within $150$ ms.

Question 7

A vehicle manufacturer is developing a new braking system. The primary safety goal for the system is to prevent unintended acceleration, which has been assigned ASIL D. To manage the complexity and development effort, the safety manager proposes decomposing this ASIL D safety goal into two independent safety goals, each assigned ASIL C. What is the expected outcome of this ASIL decomposition if the independence criteria are met and rigorously verified according to ISO 26262:2018?

Accepted Answer

The original ASIL D safety goal is considered satisfied by the combination of the two ASIL C safety goals.

Question 8

Consider a complex automotive system designed to prevent unintended acceleration, which has been assigned an ASIL D safety goal. The development team proposes to decompose this ASIL D safety goal into two independent hardware elements, each responsible for a distinct aspect of the acceleration control. What is the most appropriate ASIL assignment for each of these decomposed hardware elements to ensure the overall safety goal is met, considering the probabilistic nature of ASILs and the principles of ASIL decomposition as defined in ISO 26262:2018?

Accepted Answer

ASIL C

Question 9

Consider a complex automotive electronic control unit (ECU) responsible for managing the vehicle\'s adaptive cruise control (ACC) system. The ACC system has been assigned an ASIL C for its primary safety goal related to maintaining safe following distances. During the system design phase, the safety manager proposes decomposing the ASIL C safety requirement for safe following distance into two independent safety requirements, each allocated to separate hardware modules. Each of these new safety requirements is assessed to be of ASIL B. What is the ASIL of each of these independently decomposed safety requirements when allocated to their respective hardware modules, assuming the decomposition successfully achieves the required independence?

Accepted Answer

ASIL B

Question 10

Consider a newly developed advanced driver-assistance system (ADAS) designed to prevent unintended lane departures. The Functional Safety Concept (FSC) has identified a safety goal to mitigate the risk of the vehicle drifting out of its lane without the driver\'s intent, with an assigned ASIL C. The system architecture involves a forward-facing camera, a central processing unit, and an electric power steering (EPS) actuator. Which of the following activities most accurately represents the primary focus of the transition from the FSC to the subsequent phase of technical safety concept development for this ADAS feature?

Accepted Answer

Detailing the specific hardware components responsible for detecting lane markings and the precise algorithms for steering correction, including their fault detection and reaction mechanisms.

Question 11

Consider a newly developed advanced driver-assistance system (ADAS) designed to prevent unintended lane departure. Following a rigorous hazard analysis and risk assessment (HARA), a safety goal with ASIL C was established to mitigate the risk of the vehicle drifting out of its lane due to a sensor malfunction, leading to a potential collision. The Functional Safety Concept (FSC) outlines the functional requirement to detect and react to such deviations. Which phase or artifact within the ISO 26262 V-model is the most appropriate for detailing the specific fault tolerance time interval (FTTI) required for the system\'s safety mechanisms to prevent the hazardous event, considering the system\'s architecture and the ASIL C rating?

Accepted Answer

Technical Safety Concept (TSC)

Question 12

Consider the development of a new advanced driver-assistance system (ADAS) designed to prevent unintended lane departures. Following a thorough hazard analysis and risk assessment (HARA) for potential scenarios like driver distraction leading to lane drift, a critical safety objective is established to mitigate the risk of a severe collision. Which of the following artifacts directly serves as the foundational input for defining the specific safety mechanisms and system behaviors required to achieve this objective?

Accepted Answer

The safety goal derived from the HARA

Question 13

Consider a safety-critical automotive braking system designed to meet ASIL D requirements. The development team is meticulously planning the verification and validation strategy for its complex software architecture. Which of the following verification and validation approaches is considered the most critical for demonstrating the absence of systematic faults in this ASIL D software component, thereby ensuring compliance with the stringent requirements of ISO 26262:2018?

Accepted Answer

Comprehensive static analysis, including detailed code reviews and automated static code analysis tools, focused on identifying design and implementation flaws.

Question 14

A vehicle manufacturer is developing a braking system with an ASIL D safety goal to prevent unintended acceleration. To manage complexity, they propose decomposing this ASIL D requirement into two independent ASIL B safety mechanisms, each implemented in separate hardware and software modules. What is the most critical justification required to support the ASIL B rating of each individual safety mechanism in this decomposition strategy, according to ISO 26262:2018 principles?

Accepted Answer

Demonstration that the failure of one ASIL B mechanism does not prevent the other ASIL B mechanism from fulfilling its safety function, and that the combined residual risk meets the original ASIL D safety goal.

Question 15

Consider a complex automotive control system where a critical function, initially assigned an Automotive Safety Integrity Level (ASIL) C, is decomposed into two independent software components, each assigned an ASIL B. What is the primary implication for the safety mechanisms required for these newly decomposed ASIL B components to maintain the overall ASIL C safety goal?

Accepted Answer

The safety mechanisms for each ASIL B component must be independently verifiable and capable of detecting faults that could lead to a violation of the original ASIL C safety goal, considering potential common cause failures between the two components.

Question 16

Consider a vehicle\'s braking system where a critical safety goal has been assigned ASIL C. During the system design phase, it is determined that this safety goal can be decomposed into two independent hardware elements, each responsible for a distinct aspect of the braking actuation. The target probability of dangerous failure per hour for ASIL C is $10^{-7}$. If the system architect proposes assigning ASIL B to each of these two independent decomposed hardware elements, what is the most appropriate assessment of this proposal in relation to achieving the original ASIL C safety goal?

Accepted Answer

The proposal is insufficient, as the combined probability of failure for two ASIL B elements would exceed the target for ASIL C, necessitating a higher ASIL for the decomposed elements.

Question 17

Consider a newly developed automotive braking system component intended to achieve ASIL D for its primary safety function. During the software unit design and implementation verification phase, what level of personnel independence is mandated by ISO 26262:2018 for conducting reviews of the software unit design and implementation to ensure the highest assurance of systematic fault detection?

Accepted Answer

Reviews conducted by personnel independent of the software unit's developer.

Question 18

Consider a newly developed automotive braking system component that has been assigned an ASIL C rating based on its potential to cause unintended acceleration. During the system development phase, what combination of safety analyses would be most appropriate to demonstrate compliance with the rigor required for this ASIL, ensuring comprehensive coverage of potential failure modes and their systemic and random hardware causes?

Accepted Answer

Performing a detailed Failure Mode and Effects Analysis (FMEA) and a Fault Tree Analysis (FTA)

Question 19

Consider a complex automotive system where a safety goal has been assigned an Automotive Safety Integrity Level (ASIL) D. During the system design phase, the safety manager proposes an ASIL decomposition strategy. The proposed decomposition splits the safety goal into two independent elements: Element Alpha, assigned ASIL B, and Element Beta, assigned ASIL C. For this decomposition to be compliant with ISO 26262-9:2018, what is the primary functional safety requirement for Element Beta in relation to Element Alpha\'s potential failures?

Accepted Answer

Element Beta must implement safety mechanisms that are capable of detecting and controlling failures in Element Alpha to the extent that the original ASIL D safety goal is satisfied.

Question 20

Consider a vehicle\'s braking system where the primary control unit has been assigned an Automotive Safety Integrity Level (ASIL) D. To manage development complexity and cost, the system architect proposes an ASIL decomposition strategy, splitting the functionality into two independent channels, each targeting ASIL B. What is the most critical safety consideration that must be addressed to ensure the overall system\'s safety goal, as per ISO 26262:2018, is met under this decomposition?

Accepted Answer

Implementation of a robust safety mechanism to detect and mitigate common cause failures between the two ASIL B channels.

Question 21

Consider a complex automotive system where a safety goal with ASIL D has been established for a critical braking function. The system architect proposes ASIL decomposition for a specific software component responsible for modulating brake pressure, aiming to reduce its ASIL to B. To justify this decomposition, what is the most critical aspect that the verification activities for the decomposed software component must rigorously demonstrate according to ISO 26262:2018?

Accepted Answer

The effectiveness of the independence mechanisms implemented to prevent common cause failures with other components, thereby ensuring the decomposed element's integrity.

Question 22

Consider a vehicle\'s braking system where a critical function, initially assigned ASIL-C, is decomposed into two independent sub-functions, each assigned ASIL-B. What is the primary consideration for ensuring the integrity of the original safety goal after this decomposition, particularly concerning potential common cause failures between the two ASIL-B elements?

Accepted Answer

Ensuring sufficient independence between the two ASIL-B elements to prevent common cause failures that would violate the original ASIL-C safety goal.

Question 23

Consider a complex automotive control system where a critical function, initially assigned an Automotive Safety Integrity Level (ASIL) C, is decomposed into two independent software components, each intended to operate at ASIL B. The system\'s safety goal is to prevent unintended acceleration. What is the most appropriate approach for verifying the functional safety of these two decomposed ASIL B components in relation to the original ASIL C safety goal?

Accepted Answer

Employ verification methods appropriate for ASIL B for each component individually, supplemented by specific analyses to confirm the effectiveness and independence of the decomposition, and to assess potential common cause failures.

Question 24

Consider a vehicle\'s advanced driver-assistance system (ADAS) designed to prevent unintended lane departure. The initial safety analysis identified a critical safety goal: \"Prevent unintended lane departure leading to a collision.\" This safety goal was assigned an Automotive Safety Integrity Level (ASIL) of D. To manage the complexity and development effort, the system architect proposes decomposing this ASIL D safety goal into two independent safety goals, each assigned ASIL C: \"Detect lane markings with high fidelity\" and \"Initiate corrective steering action within a specified time.\" If the implementation of these two ASIL C safety goals demonstrably meets the independence criteria stipulated in ISO 26262, what is the effective ASIL of the *original* safety goal, \"Prevent unintended lane departure leading to a collision,\" after successful ASIL decomposition?

Accepted Answer

ASIL D

Question 25

When developing a safety-critical automotive system, what is the principal purpose of the Functional Safety Concept (FSC) as mandated by ISO 26262:2018?

Accepted Answer

To define the functional safety requirements (FSRs) and allocate them to system elements, thereby translating safety goals into implementable specifications.

Question 26

Consider a complex automotive system where a critical safety function, originally assigned ASIL C, is to be decomposed into two independent elements. The first element, implementing a portion of the original function, is to retain ASIL C. The second element, responsible for a complementary aspect of the original function, is to receive a decomposed safety goal. The decomposition mechanism employed between these elements is a safety mechanism designed to prevent common cause failures, with a proven independence and sufficient diagnostic coverage as per ISO 26262-9:2018, Clause 7.4.11. What is the highest ASIL that can be assigned to the safety goal for the second element as a direct result of this ASIL decomposition?

Accepted Answer

ASIL B

Question 27

During the development of an advanced driver-assistance system (ADAS) featuring a novel sensor fusion algorithm, a critical safety goal is to prevent unintended acceleration under specific environmental conditions. The system has been assigned ASIL D. The safety manager is reviewing the documentation flow. Which phase\'s output is most directly used as the primary input for defining both the hardware-specific safety mechanisms and the software-specific safety mechanisms to achieve the allocated safety goals?

Accepted Answer

Technical Safety Concept

Question 28

Consider a complex automotive system where an initial hazard analysis identifies a critical failure mode leading to a safety goal with an assigned ASIL D. The development team proposes an ASIL decomposition strategy, allocating the safety goal to two independent hardware elements, each designed to meet ASIL C requirements. Assuming the independence criteria and fault tolerance measures are rigorously verified and documented according to ISO 26262, what is the ASIL of the *original* safety goal that the decomposed elements are intended to fulfill?

Accepted Answer

ASIL D

Question 29

Consider a complex automotive control system where a safety goal with ASIL D has been established for a critical function. The system architect proposes to decompose this ASIL D requirement into two independent elements, each assigned ASIL B. What is the fundamental prerequisite that must be rigorously demonstrated to ensure the validity of this ASIL decomposition according to ISO 26262:2018?

Accepted Answer

The implementation of effective safety mechanisms that prevent common cause failures and mitigate potential failures in the lower ASIL elements, thereby ensuring the original safety goal's integrity.

Question 30

Consider a vehicle equipped with an advanced electronic throttle control system. During the hazard analysis and risk assessment (HARA), a critical hazard identified is unintended vehicle acceleration due to a malfunction in the throttle control. The resulting safety goal established is to prevent this unintended acceleration from leading to a collision with another vehicle or obstacle. Which of the following statements best represents a functional safety requirement derived from this safety goal, adhering to the principles of ISO 26262:2018?

Accepted Answer

The system shall detect and mitigate unintended acceleration within 50 milliseconds.

ISO 26262:2018 - Automotive Functional Safety Engineer Free Practice Test — 30 Questions

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