The question probes the understanding of the safety lifecycle and the role of the functional safety assessor in verifying the correct implementation of safety activities. Specifically, it focuses on the verification of the safety requirements derived from the hazard analysis and risk assessment (HARA) and their subsequent allocation to system elements. The assessor’s role is to ensure that these safety requirements are not only correctly derived but also demonstrably implemented and verified throughout the development process. This involves checking that the safety goals identified in the HARA are translated into specific, verifiable safety requirements, and that these requirements are then allocated to appropriate architectural elements (hardware, software, or system). The assessor must confirm that the evidence provided by the development teams demonstrates that these allocated safety requirements have been correctly implemented and validated against the safety goals. Therefore, the most critical aspect for the assessor to verify at this stage is the traceability and verification of the safety requirements from their origin in the HARA to their implementation and validation within the system architecture. This ensures that the safety case is robust and that the system meets its intended safety goals.

The core of this question lies in understanding the transition from the conceptualization of a safety goal to the concrete definition of functional safety requirements (FSRs). ISO 26262:2018, specifically Part 3 (Concept Phase) and Part 4 (Product Development at the System Level), outlines this progression. A safety goal, derived from the hazard analysis and risk assessment (HARA), represents a top-level safety objective to prevent or mitigate hazardous events. Functional safety requirements are then derived from these safety goals, detailing *what* the system must do to achieve the safety goal. This involves specifying the functional behavior, performance criteria, and operational constraints necessary to maintain safety. The ASIL (Automotive Safety Integrity Level) assigned to the safety goal directly influences the rigor and detail required in the FSRs. Therefore, the correct approach is to ensure that FSRs are a direct, traceable, and sufficiently detailed elaboration of the safety goals, addressing the identified hazards and their associated risks. Incorrect options might focus on lower-level design details (technical safety requirements), the initial hazard identification without the subsequent requirement derivation, or the validation activities that occur much later in the development lifecycle.

The core of this question lies in understanding the relationship between the Automotive Safety Integrity Level (ASIL) decomposition and the resulting safety goals. ASIL decomposition, as described in ISO 26262, allows for the derivation of lower ASILs for elements that are sufficiently independent from the elements responsible for the higher ASIL. When a safety goal with a high ASIL (e.g., ASIL D) is decomposed, the resulting safety requirements for the decomposed elements must collectively ensure that the original safety goal is still met. This means that if a system component is responsible for a portion of the overall safety function, its safety requirements will be derived from the parent safety goal but adjusted to the decomposed ASIL. For instance, if an ASIL D safety goal related to preventing unintended acceleration is decomposed into two ASIL B safety requirements for separate electronic control units (ECUs), each ECU’s safety requirements must be sufficient to contribute to the overall ASIL D objective. The safety goal for the decomposed element will inherit the hazard and the safety objective from the parent safety goal but will be assigned the lower ASIL. Therefore, the safety goal for the decomposed element will be “Prevent unintended acceleration (ASIL B),” reflecting the reduced ASIL while maintaining the essential safety objective. The other options misrepresent the outcome of ASIL decomposition by either assigning the original ASIL, introducing unrelated ASILs, or creating safety goals that are not directly derived from the parent safety goal’s hazard.

The scenario describes a situation where a safety goal has been defined for a vehicle’s braking system, specifically to prevent unintended acceleration. The ASIL (Automotive Safety Integrity Level) assigned to this safety goal is ASIL D. The question then asks about the appropriate safety mechanism to implement to achieve this safety goal, considering the ASIL D rating. ISO 26262:2018, Part 4 (Product development at the system level) and Part 5 (Product development at the hardware level) provide guidance on the selection and implementation of safety mechanisms based on ASIL. For ASIL D, a high level of diagnostic coverage and fault tolerance is required. A common and effective safety mechanism for preventing unintended acceleration, especially at ASIL D, involves redundant sensing of the accelerator pedal position and a cross-checking mechanism. If the primary and secondary sensors provide significantly different readings, a safe state can be achieved, such as limiting engine power or disabling acceleration. This approach directly addresses the potential failure of a single sensor or actuator, which is a common cause of unintended acceleration. Other options might be less effective for ASIL D. For instance, a simple plausibility check of a single sensor might not provide sufficient diagnostic coverage. A watchdog timer, while important for detecting frozen software, doesn’t directly address sensor failures leading to unintended acceleration. Implementing a completely independent braking system for this specific failure mode, while robust, might be overly complex and costly compared to redundant sensing and cross-checking for this particular safety goal. Therefore, redundant sensing with cross-checking is the most appropriate and commonly adopted safety mechanism for this scenario at ASIL D.

The question probes the understanding of the functional safety assessment process, specifically concerning the verification of safety requirements derived from the safety goals. For a given ASIL D safety goal, the associated safety requirements must be rigorously verified. Verification activities for safety requirements are typically performed through methods such as testing, analysis, and review. The objective is to confirm that the implemented system or component fulfills the intended safety function and meets the specified safety integrity level. The ASIL D designation implies the highest level of rigor is required. Therefore, a comprehensive verification strategy would involve multiple, independent verification methods to provide sufficient confidence. Considering the ASIL D, a combination of detailed static analysis of the design, extensive unit testing with high coverage metrics, integration testing to verify interactions between components, and system-level testing under various operational conditions would be essential. Furthermore, a formal review of the verification results by an independent party is a crucial step in the assessment process to ensure objectivity and thoroughness. The explanation focuses on the necessity of a multi-faceted verification approach to satisfy the stringent requirements of ASIL D, emphasizing that a single verification method is insufficient. The emphasis is on demonstrating that the safety requirements are met through evidence generated by these diverse activities.

The question probes the understanding of the functional safety assessment process, specifically concerning the verification of safety requirements derived from hazard analysis and risk assessment (HARA). The core principle is that the safety goals established during HARA must be demonstrably met by the system’s design and implementation. This involves tracing the safety goals through the subsequent phases of the safety lifecycle, including the definition of functional safety requirements (FSRs) and technical safety requirements (TSRs), and ultimately to the architectural design and verification activities. The assessor’s role is to ensure this traceability and completeness.

A key aspect of the assessment is confirming that the safety mechanisms identified to mitigate identified hazards are correctly specified and implemented. For instance, if a hazard analysis identifies a potential for unintended acceleration with a high ASIL, the safety goals would mandate preventing or mitigating this. The FSRs would then detail how this is achieved at a functional level (e.g., “The system shall prevent unintended acceleration above a defined threshold”). The TSRs would translate this into specific technical solutions (e.g., “The powertrain control unit shall monitor throttle position and engine speed, and if a discrepancy indicative of unintended acceleration is detected, it shall limit engine torque to a safe level within \(50\) ms”). The assessment verifies that these requirements are indeed derived from the safety goals and that the verification activities (e.g., testing, simulation, analysis) confirm their effectiveness.

The assessor must ensure that the safety case provides sufficient evidence that all safety goals are achieved. This evidence stems from the verification and validation activities performed throughout the development lifecycle. The assessment is not merely about checking if a safety manual exists, but about critically evaluating the evidence that the system is safe according to the defined safety goals and ASILs. Therefore, the most comprehensive and accurate response focuses on the verification of safety requirements against the established safety goals, which is the fundamental objective of the assessment in this context.

The question probes the understanding of the functional safety assessment process, specifically concerning the verification of safety requirements derived from the safety goals. The core of the assessment involves ensuring that the safety requirements are sufficiently detailed, unambiguous, and verifiable to enable the development of a safe system. This verification is a critical step in confirming that the system design effectively mitigates the identified hazards. The process requires a systematic review of the safety requirements against the safety goals and the overall system architecture. The assessment must confirm that each safety requirement directly contributes to achieving a safety goal and that its implementation can be objectively verified through testing, analysis, or review. Without this rigorous verification, there’s a risk that the implemented safety mechanisms might not adequately address the intended safety goals, potentially leading to residual risks. Therefore, the most crucial aspect of the assessment in this context is the confirmation that the safety requirements are indeed verifiable and traceable to the safety goals.

The core of this question lies in understanding the distinction between a safety goal and a functional safety requirement, particularly in the context of ISO 26262 Part 3. A safety goal is an objective that must be achieved to prevent unreasonable risk. It is typically stated at a high level, focusing on the desired outcome. Functional safety requirements, on the other hand, are derived from safety goals and specify the necessary functions and their properties to achieve the safety goal. They are more detailed and actionable, defining *how* the system should behave.

Consider a scenario where a vehicle’s braking system is being developed. A potential hazard identified is unintended acceleration. A safety goal might be to prevent unintended acceleration that could lead to a collision. This is a high-level objective. To achieve this, functional safety requirements are derived. One such requirement could be that if the accelerator pedal position sensor reports a value exceeding a certain threshold while the brake pedal is also depressed, the engine torque shall be reduced to a predefined safe level within a specified time. This is a concrete, verifiable requirement that contributes to the overarching safety goal.

Another functional safety requirement might involve the diagnostic monitoring of the accelerator pedal position sensors, ensuring that any detected fault leading to a plausible erroneous signal is reported within a specific time frame. The question asks to identify the statement that represents a functional safety requirement. Therefore, the correct option will be a statement that details a specific system behavior or property necessary to achieve a safety goal, rather than a broad statement of risk avoidance. The other options would represent either hazards, safety goals, or perhaps elements of a safety concept that are not yet detailed functional safety requirements.

The scenario describes a situation where a functional safety assessment is being conducted for a complex automotive system, specifically focusing on the verification of safety requirements derived from the hazard analysis and risk assessment (HARA). The question probes the assessor’s understanding of the appropriate methods for verifying these requirements, particularly when dealing with software components that implement safety mechanisms.

The core of the verification process for safety requirements, especially those related to software, involves demonstrating that the implemented functionality correctly addresses the identified hazards and their associated safety goals. ISO 26262:2018, particularly Part 6 (Product development at the software level) and Part 4 (Product development at the system level), outlines various verification techniques. For software safety requirements, methods like static analysis, dynamic analysis (including unit testing, integration testing, and system testing), and formal methods are crucial. The effectiveness of these methods depends on the ASIL (Automotive Safety Integrity Level) assigned to the safety goal. Higher ASILs generally mandate more rigorous and diverse verification methods.

In this context, the assessor must evaluate the evidence provided by the development team to confirm that the software correctly implements the safety mechanisms. This evidence would typically include test reports, code reviews, and potentially formal verification artifacts. The question asks for the *most appropriate* approach for the assessor to take.

Considering the options:
* Option A, focusing on the systematic execution of integration and system tests, directly addresses the verification of how the software components interact and contribute to the overall system safety. This aligns with the principles of ISO 26262 for demonstrating that safety requirements are met at the system level, especially for complex interactions. The evidence from these tests, when properly designed and executed, provides strong assurance.
* Option B, emphasizing the review of design documentation without direct testing, is insufficient for verifying the *implementation* of safety requirements. Design reviews are important for architectural correctness but do not confirm functional behavior.
* Option C, suggesting a focus solely on unit testing, is also insufficient. While unit testing verifies individual software units, it does not guarantee the correct integration and system-level behavior of safety mechanisms.
* Option D, proposing a reliance on simulation results alone, can be a supplementary method but is generally not considered a complete replacement for actual integration and system testing, especially for demonstrating the robustness of safety functions under various operational conditions.

Therefore, the most appropriate approach for the assessor is to ensure that the evidence demonstrates the correct implementation and behavior of the safety mechanisms through rigorous integration and system testing.

The correct approach involves understanding the fundamental principles of safety validation and verification within the ISO 26262 framework, specifically concerning the transition from the system level to the vehicle level. The question probes the assessor’s ability to identify the most appropriate method for confirming the functional safety of a complex automotive system, such as an advanced driver-assistance system (ADAS) incorporating radar and camera fusion, when integrated into a complete vehicle. This requires considering the limitations of purely simulation-based testing and the necessity of real-world validation to capture emergent behaviors and environmental interactions not fully representable in a simulated environment. The concept of “vehicle-level integration testing” directly addresses this need by focusing on the system’s performance and safety within its intended operational context, encompassing all relevant vehicle dynamics, environmental conditions, and interactions with other vehicle systems. This type of testing is crucial for demonstrating that the safety goals established at the system level are met in the final product, thereby fulfilling the requirements of ISO 26262 Part 4 (Product development at the system level) and Part 8 (Supporting processes, particularly clause 9 on verification). The other options represent valid testing methodologies but are either too narrow in scope (e.g., component testing, simulation testing) or represent a different phase of the safety lifecycle (e.g., hazard analysis and risk assessment, which precedes development and testing).

The question probes the understanding of the iterative nature of safety activities within the ISO 26262 framework, specifically concerning the impact of a newly identified hazard on subsequent safety lifecycle phases. When a previously unconsidered hazard is discovered during the system design phase, it necessitates a re-evaluation of the entire safety lifecycle. This re-evaluation is not confined to a single phase but must cascade through the relevant preceding and succeeding activities to ensure that the newly identified risk is adequately addressed. Specifically, the hazard analysis and risk assessment (HARA) must be revisited to determine the ASIL of the new hazard. Subsequently, the functional safety concept (FSC) and technical safety concept (TSC) need to be updated to incorporate safety requirements that mitigate this hazard. Furthermore, the verification and validation (V&V) activities must be adapted to include tests that confirm the effectiveness of these new safety measures. Therefore, the most appropriate action is to initiate a review and update of all safety-related work products that are impacted by this new hazard, ensuring consistency and completeness across the safety lifecycle. This iterative process is fundamental to achieving the required level of functional safety.

The question probes the understanding of how to manage safety requirements derived from a hazard analysis and risk assessment (HARA) within the context of ISO 26262. Specifically, it focuses on the transition from the conceptualization of safety goals and functional safety requirements (FSRs) to their concrete implementation in technical safety requirements (TSRs). The correct approach involves a systematic decomposition and refinement process. Safety goals, identified during the HARA, represent the highest level of safety objectives. These are then translated into FSRs, which define the necessary functions to prevent or mitigate identified hazards. The crucial step for the functional safety assessor is to ensure that these FSRs are correctly and completely allocated to specific system elements and further detailed into TSRs. TSRs specify the technical implementation details necessary to achieve the FSRs, including hardware and software aspects. Therefore, the most effective method for an assessor to verify the correct derivation and allocation is to trace the lineage of requirements from the safety goals through the FSRs to the TSRs, ensuring that each TSR directly supports an FSR and that all FSRs are covered by at least one TSR. This traceability is fundamental to demonstrating that the system design adequately addresses the identified risks. The other options represent incomplete or incorrect methodologies. Focusing solely on the HARA output without verifying the subsequent allocation and refinement is insufficient. Similarly, concentrating only on the final TSRs without tracing their origin from safety goals and FSRs misses critical validation points. Lastly, a process that prioritizes architectural design over the detailed allocation and refinement of safety requirements would likely lead to gaps or misinterpretations of the safety intent.

The core of this question lies in understanding the distinction between the safety goal and the functional safety requirements derived from it. A safety goal is a top-level safety objective that defines the system’s desired safe state and the conditions under which it should be achieved. Functional safety requirements, on the other hand, are more detailed specifications that describe *how* the system will achieve the safety goal. They are derived from the safety goal and are allocated to specific system elements.

Consider a scenario where a vehicle’s braking system is designed to prevent unintended acceleration. The safety goal might be: “Prevent unintended acceleration that could lead to a loss of vehicle control.” This is a high-level objective. To achieve this, functional safety requirements would be developed. For instance, a functional safety requirement could specify: “The braking system shall apply a minimum deceleration of \(0.3g\) within \(100ms\) of detecting a critical acceleration event.” This requirement is concrete, measurable, and directly contributes to achieving the broader safety goal.

Another functional safety requirement might be: “The brake pedal sensor shall have a diagnostic coverage of \(99\%\) for stuck-on faults.” This addresses the reliability of a component that enables the braking function. The explanation of why the correct option is correct is that it represents a specific, verifiable action or property that directly supports the overarching safety objective. The other options, while potentially related to safety, do not represent a direct, derived requirement from the safety goal in the same manner. For example, a system architecture description is a design artifact, not a requirement. A hazard analysis outcome is an input to defining safety goals, not a requirement itself. A verification method is a means to check compliance, not the requirement. Therefore, the option that details a specific, verifiable functional behavior or attribute that contributes to the safety goal is the correct answer.

The question probes the understanding of the safety case argumentation and its role in demonstrating the achievement of functional safety. A robust safety case is a structured argument, supported by evidence, that a system is acceptably safe for its intended purpose. It directly addresses the safety goals and requirements derived from the hazard analysis and risk assessment (HARA). The core of the safety case is to provide convincing evidence that the safety lifecycle activities have been performed correctly and that the resulting system design and implementation meet the specified safety integrity levels (ASILs). This includes evidence from various phases, such as requirements specification, design, implementation, verification, and validation. The safety case is not merely a collection of documents; it’s a coherent and verifiable argument that links the safety requirements to the implemented system and its operational context. It’s a crucial artifact for demonstrating compliance with ISO 26262 and for obtaining approval for the system’s release. Therefore, the most accurate description of its primary function is to provide a structured argument supported by evidence to demonstrate that the system is acceptably safe.

The question probes the understanding of the safety lifecycle and the role of the Functional Safety Assessor in verifying the completeness and correctness of safety activities at specific milestones. The core of ISO 26262 mandates that safety assessments are conducted at key points to ensure that the safety goals and requirements are being met throughout the development process. These assessments are not merely a final check but an integral part of the continuous safety assurance. Specifically, the transition from the concept phase to the system development phase, and then to the production and operation phases, are critical junctures where a comprehensive review is essential. The Functional Safety Assessor’s role is to provide an independent judgment on the achieved level of functional safety. This judgment is based on the evidence generated during the preceding phases. Therefore, the assessor must verify that all safety activities required by the standard have been performed and that the results are documented and satisfactory before proceeding to the next phase. This includes reviewing the hazard analysis and risk assessment (HARA), the functional safety concept, the technical safety concept, and the verification and validation activities. The assessor’s confirmation is a prerequisite for the formal release of a development phase or the entire product.

The core of this question lies in understanding the distinction between the Safety Goal and the Functional Safety Concept (FSC) within the ISO 26262 V-model. The Safety Goal is a top-level safety requirement that defines the hazard and the necessary risk reduction. It is derived from the hazard analysis and risk assessment (HARA). The FSC, on the other hand, refines the Safety Goal into specific functional requirements that are allocated to system elements. It describes *what* the system needs to do to achieve the Safety Goal, but not *how* it will be implemented.

Consider a scenario where a HARA identifies a hazard of unintended acceleration due to a sensor failure, leading to a high ASIL (e.g., ASIL D). The Safety Goal might be: “Prevent unintended vehicle acceleration that could lead to a collision.” This goal is abstract and high-level. The FSC would then detail the functional requirements to achieve this. For instance, it might specify that the system must detect sensor plausibility deviations within a certain timeframe and transition to a safe state (e.g., limp-home mode or engine shutdown) if a critical deviation is detected. The FSC would not dictate the specific hardware components (like redundant sensors or a specific microcontroller) or software algorithms (like a Kalman filter for sensor fusion) that will implement these functions. Those details belong to the Technical Safety Concept (TSC) and subsequent design phases. Therefore, the FSC bridges the gap between the abstract Safety Goal and the concrete technical implementation, focusing on the functional behavior required to mitigate the identified hazard.

The core of this question lies in understanding the cascading effects of a safety goal violation and the subsequent necessary actions as defined by ISO 26262. When a safety goal is violated, the system must transition to a safe state. The effectiveness of this transition is evaluated through verification activities. If the verification of the safety mechanism designed to achieve the safe state reveals a deficiency, this deficiency must be addressed. This typically involves a re-evaluation of the safety concept, potentially leading to a redesign of the safety mechanism or a modification of the safety goal itself if the original goal is deemed unattainable with the current architecture. The process then requires re-verification of the updated safety concept and mechanisms. Therefore, the most appropriate next step is to initiate a review of the safety concept and the associated safety mechanisms to identify the root cause of the verification failure and implement corrective actions. This iterative refinement is fundamental to achieving functional safety. The other options represent either premature conclusions or incomplete actions. Simply documenting the failure without addressing the root cause is insufficient. Implementing a workaround without a thorough review of the safety concept might introduce new hazards. A full system redesign is an extreme measure that may not be necessary if the deficiency can be addressed through targeted improvements to the safety mechanism.

The question probes the understanding of the functional safety assessment process, specifically concerning the verification of safety requirements against the system design. The core of the assessment lies in ensuring that the implemented system correctly reflects the safety goals and requirements derived during the concept phase and detailed in the safety plan. This involves a rigorous review of design artifacts, including architectural specifications, detailed design documents, and implementation code, to confirm that all safety mechanisms and properties are present and function as intended. The assessment must also consider the impact of any changes made during development, ensuring that these changes do not compromise previously verified safety aspects. The process necessitates a systematic comparison of the safety requirements (e.g., from the safety plan, safety requirements specification) with the actual system design and implementation. Therefore, the most critical aspect of the assessment in this context is the verification that the system design and implementation accurately and completely realize the specified safety requirements. This includes checking for the presence and correct functioning of safety mechanisms, adherence to safety principles, and the absence of unintended behaviors that could lead to hazardous events. The other options represent important activities within the overall safety lifecycle but are not the *most* critical verification point in this specific scenario of assessing the realization of safety requirements in the system design. For instance, confirming the completeness of the hazard analysis and risk assessment is crucial earlier in the lifecycle, and the validation of the safety goals against the intended functionality is also a prerequisite. The development of the safety case is an outcome of successful verification and validation, not the verification activity itself.

The question probes the understanding of the safety lifecycle and the role of the Functional Safety Assessor in ensuring compliance with ISO 26262:2018. Specifically, it focuses on the verification activities that are crucial at the system level, post-integration of hardware and software components. The correct approach involves assessing the effectiveness of system integration testing and validation activities against the defined safety requirements and the safety plan. This includes verifying that the system behaves as intended under various operational conditions, including fault injection scenarios, and that all safety mechanisms function correctly. The assessor must confirm that the system meets its specified safety goals and that the evidence generated during these phases adequately demonstrates this. Incorrect options would misplace the assessor’s primary verification focus, such as solely on component-level testing (which is typically done earlier), or on aspects outside the assessor’s direct purview like detailed software unit testing (which is the responsibility of the development team, though the assessor reviews the results). Another incorrect option might suggest focusing on the final production process without sufficient emphasis on the preceding system-level validation, or on the initial hazard analysis without considering the subsequent verification of mitigation strategies. The assessor’s role is to provide an independent judgment on the overall functional safety of the item, which necessitates a thorough review of all verification and validation evidence, with a particular emphasis on the system level where the integrated item is evaluated.

The correct approach involves understanding the fundamental principles of safety validation and verification within the ISO 26262 framework, specifically concerning the transition from the system level to the vehicle level. The standard emphasizes that safety validation activities must confirm that the integrated system meets its specified safety requirements and that the overall vehicle functionality is safe. This includes verifying that the safety goals defined at the vehicle level are achieved by the system’s behavior, considering all relevant operational situations and environmental conditions. The process requires a systematic evaluation of the vehicle’s safety performance, often involving integrated testing, vehicle-level simulations, and potentially field testing, to ensure that no emergent safety issues arise from the interaction of the system with other vehicle components and the external environment. The focus is on demonstrating the absence of unreasonable risk at the vehicle level, which is the ultimate objective of functional safety. This validation confirms the effectiveness of the safety measures implemented throughout the development lifecycle.

The correct approach involves identifying the most appropriate method for validating a safety mechanism designed to mitigate a specific hazardous event. In this scenario, the hazardous event is unintended acceleration due to a sensor fault, and the safety mechanism is a plausibility check that compares redundant sensor inputs. The ASIL level for this hazard is D, indicating a high criticality. For ASIL D, the standard mandates rigorous validation methods to ensure the safety mechanism’s effectiveness.

ISO 26262:2018, Part 6 (Product development at the software level) and Part 4 (Product development at the system level), along with Part 8 (Supporting processes), provide guidance on verification and validation. Specifically, Part 6, Clause 9, discusses software unit testing, integration testing, and verification of software safety requirements. Part 4, Clause 7, covers system integration and testing, including system validation. Part 8, Clause 9, emphasizes the importance of confirmation measures, which include audits and assessments.

When validating a safety mechanism for an ASIL D system, a combination of methods is typically employed. Static analysis and formal methods are crucial for demonstrating the absence of certain software errors and for verifying the correctness of the safety logic. Dynamic testing, including fault injection testing, is essential to prove that the safety mechanism behaves as intended under various fault conditions, including those that could lead to unintended acceleration. Furthermore, a safety assessment, as stipulated in Part 2 (Management of functional safety) and Part 9 (ASIL-oriented and safety-oriented analyses), is a mandatory confirmation measure to provide an independent evaluation of the safety case. This assessment would review the results of all verification and validation activities, including the effectiveness of the plausibility check.

Considering the ASIL D requirement and the nature of the safety mechanism (plausibility check for sensor redundancy), a comprehensive validation strategy would include rigorous dynamic testing with fault injection to simulate sensor failures and verify the detection and mitigation by the plausibility check. This would be complemented by static analysis to examine the software’s structure and adherence to safety coding guidelines, and formal methods to mathematically prove the correctness of the plausibility algorithm under specific conditions. Finally, a thorough safety assessment by an independent body is a critical confirmation measure to ensure that all safety requirements have been met and that the system is acceptably safe. Therefore, the combination of fault injection testing, static analysis, formal methods, and a safety assessment represents the most robust validation approach for an ASIL D safety mechanism addressing unintended acceleration.

The core of this question lies in understanding the relationship between the Automotive Safety Integrity Level (ASIL) decomposition and the resulting ASIL of the decomposed elements. ASIL decomposition is a technique permitted by ISO 26262 to reduce the ASIL of a safety element by distributing its safety requirements across multiple, independent elements. The standard specifies that if an ASIL C safety requirement is decomposed into two independent elements, each element must inherit an ASIL of C. However, if the decomposition is not perfectly independent, or if the safety goal itself is not fully covered by the decomposed elements, the ASIL of the decomposed elements might need to be adjusted. In this specific scenario, the ASIL D safety goal is decomposed into two elements, Element Alpha and Element Beta. The standard’s guidance on ASIL decomposition (Part 9, Clause 7) states that if a safety requirement of ASIL X is decomposed into two independent elements, each element shall have ASIL X. However, the question implies a scenario where the decomposition is not perfectly independent or where the coverage is not absolute, leading to a need for a higher ASIL for the decomposed elements to maintain the overall safety goal. The principle is that if the original safety goal is ASIL D, and the decomposition is not guaranteed to be fully independent or to perfectly cover the original goal, the ASIL of the decomposed elements should be at least ASIL D to ensure the overall safety integrity. Therefore, if the decomposition of an ASIL D safety goal results in two elements, and the independence or coverage is not absolute, the ASIL for each of these elements must remain ASIL D to satisfy the original safety goal’s integrity. This is a crucial aspect of ensuring that the safety mechanisms are sufficiently robust even when distributed. The rationale is that any failure in one element, even if the other is functioning, must not compromise the ASIL D integrity of the original safety goal.

The question probes the understanding of the ISO 26262:2018 standard’s requirements for the verification of safety requirements at the system level, specifically concerning the integration of safety mechanisms. The core of the question lies in identifying the most appropriate method for verifying that a newly integrated safety mechanism effectively mitigates a previously identified hazardous event. ISO 26262, particularly Part 4 (Product development at the system level) and Part 6 (Product development at the software level), emphasizes a structured approach to verification. Verification activities must confirm that safety requirements are met and that the system behaves as intended under fault conditions. For a newly integrated safety mechanism designed to mitigate a specific hazard, a rigorous verification process is essential. This process should include not only static analysis of the design and code but also dynamic testing that simulates the hazardous event and verifies the mechanism’s response. Fault injection testing is a critical technique for this purpose, as it directly assesses the effectiveness of safety mechanisms by introducing faults and observing the system’s behavior. This allows for a direct confirmation that the mechanism prevents or controls the hazardous event as specified in the safety goals. Other methods, while important in the overall safety lifecycle, are less direct for verifying the *effectiveness* of a specific *mitigation* mechanism under fault conditions. For instance, review of safety analyses (like FMEA or FTA) confirms the *design* intent but not the *actual* operational effectiveness. Code reviews focus on the implementation’s correctness but not its response to dynamic fault scenarios. Requirements traceability ensures that the mechanism is linked to the hazard but doesn’t prove its efficacy in mitigating it. Therefore, fault injection testing provides the most direct and robust evidence of the integrated safety mechanism’s performance in preventing the hazardous event.

The core of this question lies in understanding the relationship between the Automotive Safety Integrity Level (ASIL) decomposition and the resulting safety goals. ASIL decomposition, as described in ISO 26262-9:2018, allows for the reduction of the ASIL of a safety requirement for a component if that component is sufficiently independent from other components that could violate the safety goal. The principle is that if a higher-level safety goal (e.g., ASIL D) is decomposed, and the decomposition strategy ensures that the failure of a specific element does not lead to the violation of the original safety goal, then the decomposed element can be assigned a lower ASIL. Specifically, if a safety goal is decomposed into two independent safety requirements, each with ASIL C, and the failure of either one does not lead to the violation of the original ASIL D safety goal, then this is a valid decomposition. The rationale is that the probability of both independent ASIL C failures occurring simultaneously, which would then lead to the ASIL D violation, is significantly lower than the probability of a single ASIL D failure. Therefore, the correct approach involves identifying the ASIL of the original safety goal and understanding how ASIL decomposition, when applied correctly with sufficient independence, can result in lower ASILs for the decomposed elements, without compromising the overall safety integrity of the system. The key is that the decomposition must be justified by the independence of the decomposed elements and their contribution to the overall safety goal.

The core of this question lies in understanding the relationship between the Automotive Safety Integrity Level (ASIL) decomposition and the resulting ASIL of the decomposed elements. When an ASIL is decomposed, the goal is to achieve a lower ASIL for a specific element while ensuring the overall safety goal is still met. The decomposition process, as outlined in ISO 26262, allows for the allocation of safety requirements to elements with lower ASILs, provided that the decomposition is justified and the independence of the decomposed elements is maintained.

Specifically, if a safety requirement with ASIL C is decomposed into two independent elements, each element inherits a portion of the original ASIL. The standard dictates that the ASIL of the decomposed elements, when combined, must not exceed the original ASIL. A common and compliant method for decomposing ASIL C is to assign ASIL B to each of the two independent elements. This is because the probability of both independent elements failing simultaneously is significantly lower than the probability of the original element failing. The product of the probabilities of failure for independent events is the product of their individual probabilities. If we consider a simplified probabilistic view where ASIL B represents a higher probability of failure than ASIL A, and ASIL C higher than ASIL B, then assigning ASIL B to two independent elements effectively lowers the overall risk profile compared to a single ASIL C element. The rationale is that the combined effect of two ASIL B elements failing simultaneously is considered to be equivalent to or better than a single ASIL C element failing. This approach is a fundamental technique for managing complexity and cost in safety-critical systems by allowing the use of less stringent development processes for the decomposed elements, while still satisfying the original safety goal.

The question probes the understanding of the safety lifecycle and the role of the Functional Safety Assessor in the context of ISO 26262. Specifically, it focuses on the verification activities that are crucial for ensuring the integrity of safety-related elements throughout development. The correct approach involves assessing the effectiveness of verification methods applied to the safety requirements and their allocation to hardware and software components. This includes evaluating the adequacy of test cases, reviews, and analyses performed at various stages, such as the system design, hardware design, and software design phases. The assessor’s role is to provide an independent judgment on whether the safety goals have been achieved and if the implemented safety measures are sufficient to mitigate identified hazards. This involves scrutinizing the evidence generated during the development process to confirm compliance with the specified safety requirements and the overall safety concept. The assessor must ensure that the verification activities are comprehensive and that any deviations or non-conformities are properly addressed and documented. The focus is on the *process* of verification and its *effectiveness* in achieving the intended safety level, rather than the specific technical implementation details of a particular safety mechanism.

The correct approach involves understanding the fundamental principles of safety validation and verification as stipulated by ISO 26262:2018. Specifically, Part 8, Clause 7, addresses the verification of safety requirements. This clause emphasizes that verification activities must confirm that the implemented safety requirements satisfy their intended purpose and that the system behaves as specified under normal and fault conditions. The core of verification is to provide objective evidence that the work product meets its requirements. For a safety goal, this translates to ensuring that the mechanisms designed to mitigate the identified hazards are effective and that the overall system achieves the required ASIL. The other options represent activities that are either part of the broader safety lifecycle but not the direct focus of verifying a safety goal’s achievement (e.g., hazard analysis and risk assessment, which precedes the definition of safety goals), or they describe verification methods that are insufficient on their own to confirm the achievement of a safety goal without a clear link to the specific safety requirements derived from that goal. Therefore, demonstrating that the implemented safety mechanisms effectively prevent or control the hazardous events identified in the safety goal, supported by objective evidence, is the most accurate description of verifying a safety goal.

The question pertains to the verification of safety requirements derived from a hazard analysis and risk assessment (HARA) within the ISO 26262 framework. Specifically, it addresses the transition from the conceptual phase to the system design phase, focusing on the appropriate documentation and verification activities.

During the HARA, potential hazards are identified, and their severity, exposure, and controllability are assessed to determine the Automotive Safety Integrity Level (ASIL). Based on the ASIL, safety goals are established. These safety goals are then refined into functional safety requirements (FSRs). The FSRs represent the high-level functional needs to prevent or mitigate the identified hazards.

The critical step following the definition of FSRs is their allocation to system elements and the subsequent derivation of technical safety requirements (TSRs). This allocation and derivation process must be rigorously verified to ensure that the FSRs are correctly translated into implementable technical specifications. Verification at this stage typically involves reviews and analyses of the safety requirements specification document, ensuring traceability from safety goals to FSRs and then to TSRs. The confirmation that the FSRs are sufficiently detailed and unambiguous for subsequent system design is paramount.

Therefore, the most appropriate verification activity at this juncture is the review and approval of the FSRs, confirming their completeness, correctness, and traceability to the safety goals, before proceeding to the detailed system design and the derivation of TSRs. This ensures that the foundation for the entire safety lifecycle is robust and aligned with the initial risk assessment.

The core of this question lies in understanding the relationship between the Automotive Safety Integrity Level (ASIL) decomposition and the resulting safety goals and requirements. When an ASIL is decomposed, the objective is to achieve a lower ASIL for a specific element or function by introducing safety mechanisms that mitigate the risk associated with the original higher ASIL. The decomposition process itself is governed by specific criteria outlined in ISO 26262, particularly Part 9. The key principle is that the safety mechanisms introduced must be sufficiently independent and effective to reduce the probability of hazardous events to the target ASIL. Therefore, the safety goals derived from a decomposed ASIL must reflect the residual risk after the decomposition has been applied and the safety mechanisms have been implemented. This means the safety goals will be at the decomposed ASIL level, not the original ASIL. The rationale for this decomposition, including the justification for the independence and effectiveness of the safety mechanisms, must be thoroughly documented as part of the safety case. This documentation is crucial for demonstrating compliance and for the assessor to verify the validity of the decomposition. The selection of appropriate safety mechanisms and their verification is a critical step in this process.

The question probes the understanding of the safety lifecycle and the role of the safety manager in ensuring compliance with ISO 26262:2018. Specifically, it focuses on the transition from the concept phase to the system development phase, highlighting the critical activities that must be completed before proceeding. According to ISO 26262:2018, Part 2 (Management of Functional Safety), the safety plan, which includes the definition of safety activities, responsibilities, and the overall safety lifecycle, must be established and approved. Furthermore, the preliminary hazard analysis and risk assessment (HARA) must be completed to determine the ASIL for the item. The safety goals derived from the HARA are fundamental inputs for the system design. Without these foundational elements, the subsequent system development activities, such as defining the functional safety concept and technical safety concept, cannot be effectively initiated or validated against the required safety objectives. Therefore, the absence of an approved safety plan and completed HARA signifies a critical gap in the safety lifecycle, preventing a compliant transition to system development. The correct approach involves ensuring that all prerequisite safety activities, as defined by the standard and documented in the safety plan, are finalized and verified before moving to the next stage. This ensures that the development process is guided by a clear understanding of the safety requirements and the associated risks.