The correct approach involves understanding the relationship between the ASIL (Automotive Safety Integrity Level) decomposition and the resulting safety goals. When an ASIL is decomposed, the new ASILs assigned to the decomposed elements must satisfy specific criteria to ensure that the overall safety integrity is maintained. For a given ASIL \(A\), if it is decomposed into two elements with ASILs \(A_1\) and \(A_2\), the requirement is that the combination of \(A_1\) and \(A_2\) must be at least as stringent as \(A\). ISO 26262:2018 specifies that for ASIL decomposition, the resulting ASILs \(A_1\) and \(A_2\) must satisfy the condition that the probability of failure of the decomposed system is less than or equal to the probability of failure of the original system. This is often represented conceptually as \(P(failure)_{A_1} \times P(failure)_{A_2} \le P(failure)_{A}\).

In practice, this means that if an ASIL C safety goal is decomposed into two lower ASIL elements, the new ASILs must be chosen such that their combined safety integrity is equivalent to or greater than ASIL C. A common and acceptable decomposition for ASIL C is to assign ASIL B to both decomposed elements. This is because ASIL B is one level lower than ASIL C, and when two ASIL B elements are combined, their overall safety integrity is considered to be equivalent to or greater than ASIL C, effectively maintaining the required safety level. Other combinations might be possible depending on specific decomposition strategies and the interpretation of the standard, but ASIL B for both is a widely accepted and straightforward method to achieve the necessary safety integrity.

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 a top-level safety objective derived from the hazard analysis and risk assessment (HARA) that aims to prevent or mitigate identified hazards. It is typically expressed in terms of a specific hazardous event and the required safety state. Functional safety requirements, on the other hand, are derived from the safety goals and specify the necessary functions and their properties to achieve the safety goal. They are more detailed and actionable, often describing *how* the system should behave.

In the given scenario, the hazard identified is unintended acceleration due to a faulty throttle control system. The safety goal is to prevent injury or damage from this unintended acceleration. The statement “The system shall detect and mitigate unintended throttle opening above a predefined threshold within \(100\) ms” directly describes a specific function, its performance criteria (detection and mitigation), and a time constraint. This is a clear example of a functional safety requirement that contributes to achieving the overarching safety goal. It details a necessary behavior of the system to ensure safety.

The other options represent different aspects of the safety lifecycle or different levels of abstraction. A safety plan outlines the overall safety activities. A technical safety requirement would be a more detailed, hardware/software-specific requirement derived from the functional safety requirements. A verification criterion is a condition used to confirm that a requirement has been met. Therefore, the statement provided most accurately aligns with the definition and purpose of a functional safety requirement.

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 the original ASIL for the overall system by implementing lower ASILs for specific elements, provided that the decomposition is justified and the safety mechanisms are correctly applied. Specifically, if an ASIL C safety goal is decomposed into two elements, each requiring ASIL B, the intention is that the combination of these ASIL B elements, through appropriate safety mechanisms, will collectively satisfy the ASIL C requirement. This implies that the safety requirements derived from the decomposed ASIL B elements must be sufficient to mitigate the hazards associated with the original ASIL C safety goal. Therefore, the safety requirements for the decomposed elements should reflect the ASIL B level, not the original ASIL C. This approach is a fundamental aspect of ASIL decomposition as described in ISO 26262, Part 9. The goal is to manage complexity and cost by applying less stringent, but still robust, safety measures to individual components while maintaining the overall system safety integrity.

The core of this question lies in understanding the relationship between ASIL decomposition and the resulting safety goals. When an ASIL decomposition is performed, the higher ASIL requirement is distributed among multiple lower ASIL elements. The safety goal for the decomposed element must still satisfy the original ASIL, but the methods and rigor applied to achieve it are tailored to the lower ASILs of the individual components. Specifically, if a safety goal with ASIL C is decomposed into two elements, one ASIL B and one ASIL A, the safety goal for the ASIL B element must still address the original hazard that led to ASIL C. The decomposition does not reduce the criticality of the hazard itself, but rather the responsibility for mitigating it. Therefore, the safety goal for the ASIL B element must be derived from the original ASIL C safety goal, ensuring that the combined effect of the decomposed elements, when analyzed with appropriate independence, meets the original ASIL C requirement. The ASIL A element would have its own safety goals derived from the same original hazard, but with less stringent requirements due to its lower ASIL. The ASIL B element’s safety goal is not simply “ASIL B,” but rather a safety goal that contributes to achieving the original ASIL C.

The correct approach involves understanding the relationship between the ASIL (Automotive Safety Integrity Level) of a safety goal and the required rigor for its decomposition into hardware and software requirements. For a safety goal with ASIL D, the decomposition process must ensure that the resulting lower-level requirements maintain the necessary safety integrity. ISO 26262 Part 4 (Product development at the system level) and Part 5 (Product development at the hardware level) and Part 6 (Product development at the software level) provide guidance on this. Specifically, Part 4, Clause 7.4.4, discusses the decomposition of safety requirements. When decomposing an ASIL D safety goal, the resulting requirements for hardware and software must also inherit a high level of integrity. While it’s not a direct mathematical division of ASILs, the principle is that the safety mechanisms and development processes for ASIL D must be applied to the decomposed elements to achieve the overall safety objective. Therefore, if a safety goal has ASIL D, the corresponding hardware and software requirements derived from its decomposition should also be treated with ASIL D rigor, necessitating stringent development and verification methods as outlined in the standard for that ASIL. This ensures that the system’s safety is not compromised by the decomposition process.

The core of this question lies in understanding the distinction between a safety goal and a functional safety requirement, particularly in the context of deriving safety requirements from higher-level safety goals. A safety goal is an objective to prevent or mitigate hazards. Functional safety requirements specify the safety functions that must be implemented to achieve the safety goals.

Consider a scenario where a hazard analysis identifies the risk of unintended acceleration due to a sensor failure. The ASIL determination for this hazard might lead to ASIL D. A corresponding safety goal could be: “Prevent unintended vehicle acceleration exceeding a defined threshold.”

From this safety goal, functional safety requirements are derived. These requirements detail *how* the system will achieve the safety goal. For instance, a functional safety requirement might state: “The powertrain control system shall detect a plausibility mismatch between the throttle pedal position sensor and the vehicle speed sensor within \(100\) ms and transition to a safe state (e.g., idle speed) within \(200\) ms.” This requirement is directly traceable to the safety goal and defines a specific safety function.

The other options represent different stages or types of requirements within the ISO 26262 framework. Technical safety requirements are derived from functional safety requirements and specify the technical implementation details. Safety mechanisms are specific design elements or algorithms that implement safety requirements. System design specifications are broader documents outlining the overall system architecture and behavior, which may include safety aspects but are not the direct derivation of a safety goal into a specific safety function. Therefore, the most accurate description of the statement “The powertrain control system shall detect a plausibility mismatch between the throttle pedal position sensor and the vehicle speed sensor within \(100\) ms and transition to a safe state (e.g., idle speed) within \(200\) ms” in relation to the safety goal “Prevent unintended vehicle acceleration exceeding a defined threshold” is that it is a functional safety requirement.

The core of this question lies in understanding the relationship between ASIL (Automotive Safety Integrity Level) decomposition and the resulting safety goals. When an ASIL is decomposed, the goal is to reduce the ASIL of a lower-level component or element while still achieving the required safety of the higher-level function. This decomposition is permissible under specific conditions outlined in ISO 26262, particularly concerning the independence of the decomposed elements.

Consider a safety goal with ASIL D. If this safety goal is decomposed into two independent safety goals, each with ASIL C, the rationale is that the failure of one decomposed element does not affect the safety function of the other. The standard specifies that the ASIL of the original safety goal can be met by the combination of these lower ASIL decomposed goals, provided sufficient independence is demonstrated. The independence requirement is crucial; if the decomposed elements are not sufficiently independent, the ASIL decomposition is invalid, and the original ASIL D would need to be maintained or addressed differently. Therefore, the most appropriate outcome of a successful ASIL decomposition of ASIL D into two independent elements, each assigned ASIL C, is that the original ASIL D safety goal is considered satisfied by the combination of these ASIL C goals. This reflects the principle that the combined probability of failure of the independent ASIL C elements, when properly managed, can achieve the target safety integrity of the ASIL D.

The core of this question lies in understanding the relationship between the Automotive Safety Integrity Level (ASIL) decomposition and the resulting safety requirements. When an ASIL is decomposed, the goal is to derive lower ASILs for individual elements that, when combined, satisfy the original higher ASIL. Specifically, for ASIL D, decomposition into two ASIL C elements is a common strategy. This is because the probability of failure for two independent ASIL C elements, when combined, is generally considered to be less than the probability of failure for a single ASIL D element. The fundamental principle is that the safety goal associated with the ASIL D requirement must still be met. If an ASIL D requirement is decomposed into two ASIL C elements, and these elements are assumed to be independent, the probability of both failing simultaneously is the product of their individual probabilities of failure. For ASIL C, the target probability of failure per hour is typically in the range of \(10^{-7}\) to \(10^{-6}\). If we consider the upper bound of ASIL C, \(10^{-6}\) failures per hour, and assume two independent ASIL C elements, the combined probability of failure would be \(10^{-6} \times 10^{-6} = 10^{-12}\) failures per hour. This is significantly lower than the ASIL D target, which is typically in the range of \(10^{-8}\) to \(10^{-7}\) failures per hour. Therefore, decomposing ASIL D into two ASIL C elements is a valid method to achieve the safety goal, provided the independence assumption holds and the specific failure rates are managed. The explanation focuses on the probabilistic reasoning behind ASIL decomposition, highlighting how the combination of lower ASIL elements can achieve the safety integrity of a higher ASIL, emphasizing the importance of independence and the target probability ranges for each ASIL.

The core of this question lies in understanding the relationship between ASIL (Automotive Safety Integrity Level) decomposition and the resulting ASIL of the decomposed elements. When an ASIL C function is decomposed into two independent ASIL B functions, the ASIL of each decomposed function is determined by the ASIL of the original function and the independence achieved through decomposition. According to ISO 26262-9:2018, Clause 6.4.3, if a safety requirement of ASIL C is decomposed into two safety requirements of ASIL B, and these decomposed requirements are allocated to elements that are sufficiently independent, the resulting ASIL for each of these decomposed elements is ASIL B. The independence is crucial; if the decomposition does not achieve sufficient independence, the ASIL of the decomposed elements would need to be higher than ASIL B to cover the original ASIL C. However, the premise of the question states successful decomposition into independent ASIL B functions. Therefore, the ASIL of the decomposed elements remains ASIL B.

The core of this question lies in understanding the transition from the Functional Safety Concept (FSC) to the Technical Safety Concept (TSC) as defined in ISO 26262. The FSC outlines the safety goals and functional safety requirements at a system level, often abstractly. The TSC, however, must specify *how* these functional safety requirements are to be implemented at a technical level, considering the chosen architecture and hardware/software elements. This involves allocating safety requirements to specific hardware components, defining safety mechanisms, and specifying their behavior. Therefore, the TSC is where the abstract safety goals are translated into concrete technical specifications for implementation. The other options represent earlier or later stages in the safety lifecycle. The Hazard Analysis and Risk Assessment (HARA) precedes the FSC and identifies hazards and ASILs. The Safety Validation phase occurs after implementation and verification to confirm that the safety requirements have been met. The Software Safety Requirements Specification is a part of the TSC, but the TSC itself is the broader concept of translating FSC to technical implementation.

The core of this question lies in understanding the hierarchical nature of safety requirements and their allocation within the ISO 26262 framework, specifically concerning the transition from the Functional Safety Concept (FSC) to the Technical Safety Concept (TSC). The Vehicle-level safety requirements, derived from the hazard analysis and risk assessment (HARA), form the highest tier. These are then refined into functional safety requirements at the system level, which are documented in the FSC. The FSC specifies *what* the system must do to achieve safety, but not *how*. The TSC, on the other hand, details *how* these functional safety requirements are to be implemented at the hardware and software levels. This involves specifying technical safety requirements (TSRs) for specific elements, including their safety mechanisms, diagnostic coverage, and fault reaction times. Therefore, the most appropriate place to define the specific fault tolerance time interval (FTTI) for a particular safety goal, considering its ASIL and the system’s architecture, is within the Technical Safety Concept, as it directly informs the design of safety mechanisms and their performance. The FSC would state the need for a certain level of fault tolerance, but the precise timing is a technical implementation detail. The safety plan outlines the overall safety activities and schedule, while the safety case provides evidence of achieved safety.

The core of this question lies in understanding the distinction between the safety goal and the functional safety concept within the ISO 26262 framework. A safety goal is a top-level safety requirement derived from the hazard analysis and risk assessment (HARA) that defines the highest level of safety to be achieved for a specific hazardous event. It specifies the necessary risk reduction. The functional safety concept, on the other hand, elaborates on how the safety goal is to be achieved by defining the safety functions and their attributes. It translates the “what” of the safety goal into the “how” of the system’s behavior. Therefore, a safety goal is a prerequisite for developing the functional safety concept, as the latter is designed to fulfill the former. The other options represent different stages or artifacts within the safety lifecycle. A technical safety concept details the implementation of the functional safety concept at a system and hardware/software level. The safety plan outlines the overall safety activities and their management. The safety case provides evidence that the system is acceptably safe. Thus, the direct relationship is that the safety goal informs and dictates the requirements of the functional safety concept.

The core of this question lies in understanding the relationship between the Automotive Safety Integrity Level (ASIL) and the required rigor in the verification and validation (V&V) activities for software components. ISO 26262:2018, particularly in Part 6 (Product development at the software level), specifies different V&V methods and their applicability based on ASIL. For ASIL D, the highest ASIL, a comprehensive set of V&V techniques is mandated to achieve the necessary confidence in the software’s safety. This includes static analysis, dynamic analysis, and various forms of testing, such as unit testing, integration testing, and system testing, all performed with a high degree of independence and thoroughness. The question probes the understanding of which V&V approach is *most* critical for demonstrating the absence of systematic faults in ASIL D software, considering the inherent complexity and potential for subtle errors. While all listed activities contribute to overall safety, the systematic nature of faults in complex software, especially at ASIL D, necessitates rigorous static analysis to detect design and coding flaws early. Dynamic analysis and testing are crucial for verifying runtime behavior and detecting random hardware faults, but the proactive identification of systematic flaws through static methods is paramount for ASIL D. Therefore, a robust static analysis process, including code reviews, static code analysis tools, and formal methods where applicable, is the most direct and effective means to address the systematic fault avoidance requirements for ASIL D software.

The core of this question lies in understanding the relationship between ASIL decomposition and the requirements for safety mechanisms. ASIL decomposition, as defined in ISO 26262, allows for the reduction of the ASIL of a component if it is sufficiently independent from other components and if the decomposition is justified by a safety analysis. Specifically, Part 9, Clause 6 of ISO 26262:2018 details the principles of ASIL decomposition. The rationale for decomposition must demonstrate that the probability of common cause failures between the decomposed elements is sufficiently low. This often involves implementing independent safety mechanisms or ensuring sufficient independence in hardware and software.

When a higher ASIL element (e.g., ASIL D) is decomposed into two lower ASIL elements (e.g., ASIL B), the safety goal associated with the original ASIL D must still be met. If the decomposition is achieved by implementing two independent safety mechanisms, each at ASIL B, the combination of these two mechanisms must provide the required safety integrity level. The independence is crucial; if the two ASIL B mechanisms share common failure modes that could lead to the same hazardous event, the decomposition is invalid. Therefore, the safety mechanisms must be designed to be robust against common cause failures. The question asks for the most appropriate justification for the ASIL B rating of the *individual* safety mechanisms. The correct approach is to ensure that the failure of one ASIL B mechanism does not prevent the other ASIL B mechanism from performing its safety function, and that the combined residual risk meets the original ASIL D target. This is achieved by demonstrating sufficient independence and the absence of significant common cause failure potential.

The core of this question lies in understanding the relationship between ASIL decomposition and the required safety mechanisms for the decomposed elements. When an ASIL C function is decomposed into two ASIL B functions, the original ASIL C requirements must still be met. ISO 26262:2018, Part 9, Clause 6, addresses ASIL decomposition. Specifically, it states that if an ASIL C element is decomposed into two ASIL B elements, the safety mechanisms for the ASIL B elements must be sufficient to achieve the ASIL C safety goals. This implies that the safety mechanisms for each ASIL B element must be more robust than what would typically be required for a standalone ASIL B function, to compensate for the loss of the ASIL C integrity from the original single element. The concept of “freedom from interference” between the decomposed elements is paramount. Therefore, the safety mechanisms for each ASIL B element must be independently verifiable and capable of detecting and controlling faults that could lead to a violation of the ASIL C safety goal, even when considering common cause failures between the two decomposed elements. This often necessitates more stringent measures than simply applying standard ASIL B safety mechanisms to each decomposed part in isolation. The goal is to ensure that the combined effect of the two ASIL B elements, with their respective safety mechanisms, provides an equivalent level of safety to the original ASIL C element.

The correct approach involves understanding the relationship between the ASIL (Automotive Safety Integrity Level) decomposition and the resulting safety goals. When an ASIL is decomposed, the new ASILs assigned to the decomposed elements must satisfy the condition that the probability of failure of the original safety goal is met by the combination of the decomposed elements. Specifically, if a safety goal has ASIL C, and it is decomposed into two independent elements, each with ASIL B, the combined probability of failure of these two elements must be less than or equal to the probability of failure of the original ASIL C safety goal.

For ASIL C, the target probability of failure for a dangerous failure per hour is typically in the range of \(10^{-7}\) to \(10^{-6}\). Let’s consider the lower bound for ASIL C, which is \(10^{-7}\) failures per hour. If this is decomposed into two independent elements, each with ASIL B, the target probability of failure for ASIL B is typically in the range of \(10^{-6}\) to \(10^{-5}\).

The condition for successful ASIL decomposition, assuming independence, is that the probability of failure of the original safety goal (\(P_{SG}\)) is less than or equal to the sum of the probabilities of failure of the decomposed elements (\(P_{elem1} + P_{elem2}\)). If \(P_{SG}\) corresponds to ASIL C (e.g., \(10^{-7}\)), and we decompose it into two elements, each with ASIL B (e.g., \(10^{-6}\)), then \(P_{elem1} + P_{elem2} = 10^{-6} + 10^{-6} = 2 \times 10^{-6}\). This sum (\(2 \times 10^{-6}\)) is greater than the target probability for ASIL C (\(10^{-7}\)). Therefore, simply assigning ASIL B to both decomposed elements is not sufficient to meet the original ASIL C requirement.

To meet the ASIL C requirement of \(10^{-7}\) with two independent decomposed elements, the probability of failure for each element must be significantly lower. If we aim for the lower bound of ASIL C (\(10^{-7}\)), and we have two identical independent elements, then the probability of failure for each element (\(P_{elem}\)) must satisfy \(2 \times P_{elem} \le 10^{-7}\), which means \(P_{elem} \le 0.5 \times 10^{-7}\). This probability level (\(0.5 \times 10^{-7}\)) falls within the range for ASIL D (\(10^{-8}\) to \(10^{-7}\)). Thus, the decomposed elements would need to be assigned ASIL D.

The explanation focuses on the probabilistic argument behind ASIL decomposition. The core principle is that the combined safety integrity of the decomposed elements must be at least as stringent as the original safety goal. When a higher ASIL is decomposed, the resulting ASILs for the sub-elements must be chosen such that their combined failure probabilities, when considered in their respective safety mechanisms, do not exceed the target probability of the original safety goal. This often means that the decomposed elements might need to have a higher ASIL than initially assumed if the decomposition is not perfectly balanced or if the original ASIL is very stringent. The independence assumption is crucial here; if elements are not independent, the calculation becomes more complex, involving conditional probabilities.

The core of this question lies in understanding the relationship between the ASIL (Automotive Safety Integrity Level) of a safety goal and the required rigor for its verification activities, specifically within the context of ISO 26262:2018 Part 6 (Product development at the software level). For a safety goal with ASIL D, the standard mandates a high level of independence for verification reviews. Specifically, Part 6, Table 13 (Verification of software unit design and implementation) and Table 14 (Verification of software integration and testing) indicate that for ASIL D, reviews of software unit design and implementation, as well as software integration and testing, should be performed by personnel independent of the developer. This independence is crucial to ensure an objective assessment of the software’s compliance with safety requirements and to detect potential systematic faults that might be overlooked by the original developer. While other ASILs may require reviews, the level of independence specified for ASIL D is the most stringent. Therefore, the most appropriate verification measure for a safety goal with ASIL D, concerning software unit design and implementation reviews, is to have them conducted by personnel independent of the software unit’s developer.

The core of this question lies in understanding the relationship between the Automotive Safety Integrity Level (ASIL) and the required rigor of safety analyses. For a system with a determined ASIL C, the standard mandates specific methods and levels of detail for safety analyses. Specifically, ISO 26262 Part 4 (Product development at the system level) and Part 5 (Product development at the hardware level) outline the expectations. Part 4, Clause 7.4.4, details the requirements for safety analyses. For ASIL C, a Failure Mode and Effects Analysis (FMEA) is a fundamental requirement. Furthermore, the standard emphasizes the need for analyses that can detect systematic faults and hardware random failures. A Fault Tree Analysis (FTA) is a top-down deductive failure analysis that is highly effective in identifying the root causes of system failures and assessing the probability of a hazardous event occurring, making it a suitable complementary analysis for ASIL C. The combination of FMEA and FTA provides a robust approach to satisfying the analytical requirements for ASIL C, ensuring that potential failure modes are identified and their impact on safety goals is understood. Other analyses like Dependent Failure Analysis (DFA) are also important, particularly for higher ASILs or complex systems, but FMEA and FTA are foundational for ASIL C. A Hazard and Risk Analysis (HARA) is performed earlier in the lifecycle to determine the ASIL itself, not as a subsequent analysis to confirm ASIL rigor.

The correct approach involves understanding the relationship between ASIL decomposition and the requirements for safety mechanisms. ASIL decomposition, as defined in ISO 26262-9:2018, allows for the reduction of the ASIL of a component if it is sufficiently independent from other components and if the safety mechanisms implemented in the higher ASIL component effectively mitigate the risks associated with the lower ASIL component’s potential failures. Specifically, if a safety goal with ASIL D is decomposed into two elements, one ASIL B and one ASIL C, the ASIL C element must implement safety mechanisms that are sufficient to ensure the safety goal is met, even if the ASIL B element fails. The independence criteria (e.g., common cause failures, latent faults) must be rigorously analyzed. The ASIL C element’s safety mechanisms must be designed to achieve the safety goal’s integrity level. This means that the ASIL C element must be able to detect and control failures in the ASIL B element to prevent hazardous events. The independence of the ASIL B and ASIL C elements is crucial; if they share common causes of failure or if faults in the ASIL B element can remain latent and unrevealed by the ASIL C element’s mechanisms, the decomposition is invalid. Therefore, the ASIL C element must provide sufficient safety coverage to compensate for the reduced ASIL of the ASIL B element, ensuring the overall safety goal is met.

The question probes the understanding of the relationship between ASIL decomposition and the requirements for safety mechanisms in a redundant system. ASIL decomposition, as defined in ISO 26262-9:2018, allows for the allocation of a lower ASIL to a component if it is sufficiently independent from other components and if appropriate safety mechanisms are implemented to prevent common cause failures. For a system with a target ASIL D, if ASIL decomposition is applied to two independent channels, each achieving ASIL B, the safety goal for the overall system must still be met. This implies that the safety mechanisms within each ASIL B channel must be sufficient to mitigate the risks associated with the ASIL D requirement, considering potential common cause failures. The requirement for a safety mechanism to detect and mitigate common cause failures between the decomposed ASIL B channels is paramount. This mechanism must be designed to ensure that a failure in one channel does not propagate to the other in a way that compromises the overall safety goal. Therefore, the most critical aspect is the effectiveness of the common cause failure mitigation strategy. The other options are less critical or represent different aspects of functional safety. For instance, ensuring the independence of the ASIL B channels is a prerequisite for decomposition, but the question focuses on the *consequences* of decomposition and the necessary safety measures. The verification of the ASIL B compliance for each individual channel is also necessary, but it doesn’t directly address the common cause failure aspect that arises from decomposition. Finally, the documentation of the ASIL decomposition rationale is a procedural requirement, not a technical safety mechanism itself.

The correct approach involves understanding the relationship between ASIL decomposition and the requirements for safety element verification. ASIL decomposition, as defined in ISO 26262-9:2018, allows for the reduction of the ASIL of a component if it is sufficiently independent from other components that could violate the safety goal. However, the independence must be demonstrated through specific measures, including the verification of the decomposed element. Part 6 of ISO 26262-2018, specifically Clause 7.4.11, addresses the verification of safety elements. It states that if ASIL decomposition is applied, the verification of the decomposed element must demonstrate that the decomposition criteria are met. This includes verifying the independence of the decomposed element from other elements that could cause a common cause failure. Therefore, the verification of the decomposed element must include evidence that the independence mechanisms are effective, which directly relates to ensuring the absence of latent faults that could compromise the safety goal. The other options are incorrect because they either misrepresent the purpose of ASIL decomposition, focus on irrelevant aspects of verification, or suggest a less rigorous approach than required by the standard for demonstrating the effectiveness of decomposition. For instance, focusing solely on the ASIL of the higher-level safety goal without verifying the decomposed element’s independence is insufficient. Similarly, verifying only the functional requirements without considering the independence mechanisms would not satisfy the standard’s intent.

The core of this question lies in understanding the relationship between ASIL decomposition and the resulting safety requirements for the decomposed elements. When an ASIL-C function is decomposed into two ASIL-B functions, the safety goal for the original ASIL-C function must be achieved by the combination of the two ASIL-B functions. This means that the safety mechanisms and their independence must be sufficient to prevent common cause failures that would lead to the violation of the original safety goal. Specifically, the independence requirement for ASIL decomposition states that the decomposed elements must be sufficiently independent to prevent a single random hardware failure from causing both decomposed elements to fail in a way that violates the safety goal. This independence is typically achieved through measures like spatial separation, electrical isolation, or diverse implementation. Therefore, the safety requirements for the decomposed elements must ensure that the combined probability of failure of both elements, considering potential common cause failures, is less than or equal to the target ASIL-C probability of failure. The safety mechanisms implemented for each ASIL-B element must be designed to prevent the propagation of faults and ensure that a failure in one does not impact the other in a way that compromises the overall safety goal. The concept of ASIL decomposition is detailed in ISO 26262-9:2018, Clause 7.4.2.

The core of this question lies in understanding the relationship between ASIL decomposition and the requirements for safety element verification. When an ASIL C function is decomposed into two ASIL B elements, the verification of the resulting ASIL B elements must adhere to the methods and rigor specified for ASIL B. This means that while the original ASIL C requirement is met through the combined ASIL B elements, each individual ASIL B element’s verification cannot simply rely on ASIL B methods if the decomposition itself introduces new potential failure modes or dependencies that could impact the overall safety goal. ISO 26262:2018, Part 9, Clause 7, specifically addresses ASIL decomposition. It states that the decomposition shall be performed such that the safety requirements of the original ASIL are met, and the safety mechanisms of the decomposed elements are sufficient. Crucially, the verification of the decomposed elements must ensure that the decomposition itself does not introduce new hazards or compromise the safety integrity of the original ASIL C. Therefore, while the decomposed elements are ASIL B, their verification must consider the context of their ASIL C origin and the potential for common cause failures or cascading effects that might necessitate more stringent verification than typically applied to standalone ASIL B elements. This leads to the conclusion that a combination of ASIL B verification methods and specific analyses to confirm the effectiveness of the decomposition is required. The calculation is conceptual: ASIL C requirement decomposed into two ASIL B elements. Verification of ASIL B elements must consider the decomposition. Therefore, verification includes ASIL B methods plus specific decomposition verification.

The core of this question lies in understanding the relationship between the Automotive Safety Integrity Level (ASIL) decomposition and the resulting safety goals for a complex system. ASIL decomposition, as defined in ISO 26262, allows for the reduction of the ASIL of a safety requirement if it is implemented in a way that ensures sufficient independence from other safety mechanisms. Specifically, if a safety goal with ASIL D is decomposed into two independent safety goals, each with ASIL C, and these two ASIL C safety goals are implemented with sufficient independence, then the original ASIL D safety goal is considered satisfied. The independence criteria are crucial here, meaning that a single random hardware failure or systematic fault should not be able to affect both decomposed safety goals simultaneously. The question asks for the *minimum* ASIL that the *original* safety goal would be considered to have if the decomposition were successful. Since the decomposition results in two ASIL C elements that, when combined with sufficient independence, fulfill the ASIL D requirement, the original safety goal’s integrity is maintained at ASIL D. The decomposition process does not lower the inherent safety requirement of the original goal; it provides a means to achieve it through a different architectural approach. Therefore, the original safety goal’s integrity level remains ASIL D, as the decomposition is a method to achieve this, not a reduction of the target safety level.

The correct approach involves identifying the primary objective of a Functional Safety Concept (FSC) as defined by ISO 26262. The FSC translates the safety goals from the Hazard Analysis and Risk Assessment (HARA) into specific technical requirements for the system. It details the functional safety requirements (FSRs) that must be implemented to achieve the safety goals. This includes defining the safety mechanisms, their allocation to architectural elements, and the necessary performance criteria. The FSC serves as the foundation for subsequent development phases, ensuring that the safety objectives are systematically addressed throughout the product lifecycle. It is crucial for establishing the link between the high-level safety goals and the detailed design specifications, thereby ensuring that the system will operate safely under all foreseeable conditions. The FSC is not primarily about defining the ASIL decomposition strategy, nor is it solely focused on the verification and validation plan, although these are related activities. It also does not directly specify the detailed hardware or software design, which are derived from the FSC.

The core of this question lies in understanding the relationship between ASIL decomposition and the resulting safety goals and requirements for the decomposed elements. When an ASIL decomposition is performed, the higher ASIL safety goal is decomposed into lower ASIL safety goals for the elements that will implement the decomposed functionality. The ASIL of the decomposed safety goal for the receiving element is determined by the ASIL of the original safety goal and the effectiveness of the safety mechanism used for decomposition. In this scenario, the original safety goal has an ASIL C. The decomposition mechanism is a safety mechanism that is considered sufficiently robust to prevent common cause failures between the original ASIL C function and the decomposed ASIL B function. According to ISO 26262-9:2018, Clause 7.4.11, if the decomposition is performed by a safety mechanism that prevents common cause failures, the ASIL of the decomposed safety goal for the receiving element can be reduced. Specifically, if the decomposition mechanism is sufficiently robust, the ASIL of the decomposed safety goal can be reduced by at most two ASIL levels. Therefore, an ASIL C safety goal can be decomposed into an ASIL B safety goal for the receiving element. The safety requirements derived from this ASIL B safety goal will then be implemented in the receiving element. The other options represent incorrect ASIL assignments. Reducing ASIL C to ASIL A would imply a reduction of more than two ASIL levels, which is not permissible without further justification or a different decomposition strategy. Maintaining ASIL C for the decomposed element would negate the purpose of decomposition, which is to reduce the ASIL of certain elements. Decomposing to ASIL D is illogical as decomposition aims to reduce, not increase, the ASIL.

The core of this question lies in understanding the hierarchical nature of safety requirements and how they are refined throughout the V-model. The Functional Safety Concept (FSC) defines the safety goals and functional safety requirements at a high level. These are then allocated to system elements in the Technical Safety Concept (TSC). The Hardware Safety Requirements (HSR) and Software Safety Requirements (SSR) are derived from the TSC, detailing the specific safety mechanisms and their implementation at the hardware and software levels, respectively. Therefore, the TSC serves as the crucial intermediary, translating the abstract functional safety requirements into concrete technical specifications for hardware and software. The FSC is too high-level, and HSR/SSR are too detailed and specific to hardware/software respectively to be the direct source for deriving requirements for *both* hardware and software components in a unified manner. The safety plan outlines the overall safety activities but does not contain the detailed technical requirements themselves.

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 defined in ISO 26262, allows for the reduction of the ASIL of a safety requirement if it is allocated to multiple independent elements, each with a lower ASIL, such that the probability of common cause failures is sufficiently mitigated. Specifically, if a safety goal with ASIL D is decomposed into two independent elements, each achieving ASIL C, and the independence is rigorously demonstrated, the overall safety goal is considered met. The question asks about the ASIL of the *original* safety goal. The decomposition process does not change the inherent criticality of the original safety goal; it merely provides a method to achieve that safety goal with lower ASIL components. Therefore, if the original safety goal was ASIL D, it remains ASIL D, regardless of the decomposition strategy. The decomposition is a means to an end, not a redefinition of the original hazard’s severity. The explanation focuses on the principle that ASIL decomposition is a method to manage the implementation of safety requirements derived from a safety goal, not to alter the safety goal’s ASIL itself. The effectiveness of decomposition relies on demonstrating independence and sufficient fault detection/control mechanisms within the decomposed elements to collectively achieve the original safety goal’s integrity level.

The core of this question lies in understanding the relationship between ASIL decomposition and the requirements for safety mechanisms. ASIL decomposition, as defined in ISO 26262, allows for the reduction of the ASIL of a component if it is sufficiently independent from other components and if appropriate safety mechanisms are implemented to prevent common cause failures. Specifically, Part 9, Clause 6 of ISO 26262:2018 details the principles of ASIL decomposition. When a higher ASIL element is decomposed into lower ASIL elements, the safety goal associated with the original higher ASIL must still be achieved. This is typically done by ensuring that the lower ASIL elements, when combined with appropriate safety mechanisms, provide the necessary safety integrity. The safety mechanisms must be designed to prevent systematic failures and random hardware failures that could lead to the violation of the safety goal. These mechanisms must also be sufficiently independent to avoid common cause failures between the decomposed elements. Therefore, the presence of robust safety mechanisms that mitigate potential failures in the lower ASIL components is paramount for the validity of ASIL decomposition. The other options are incorrect because they either misrepresent the purpose of ASIL decomposition (e.g., solely for cost reduction without safety justification) or overlook the critical role of safety mechanisms in ensuring the overall safety integrity when decomposition is applied. The focus is on maintaining the safety goal, not simply on reducing the ASIL of individual components in isolation.

The core of this question lies in understanding the distinction between a safety goal and a functional safety requirement. A safety goal, derived from the hazard analysis and risk assessment (HARA), represents a top-level safety objective to prevent or mitigate identified hazards. Functional safety requirements, on the other hand, are derived from the safety goals and specify the necessary functions and their properties to achieve those goals. Specifically, a functional safety requirement must be verifiable and directly contribute to the fulfillment of a safety goal.

In the given scenario, the hazard identified is unintended acceleration. The safety goal is to prevent this unintended acceleration from causing a collision. A functional safety requirement must then detail *how* this prevention will be achieved at a functional level.

Option A, “The system shall detect and mitigate unintended acceleration within 50 milliseconds,” directly addresses the hazard and proposes a functional behavior with a quantifiable performance metric (detection and mitigation within 50 ms). This is a clear, verifiable functional safety requirement that supports the safety goal.

Option B, “The braking system shall have a minimum deceleration rate of 0.8g,” is a technical safety requirement, likely derived from a functional safety requirement, specifying a performance characteristic of a specific component. It doesn’t describe the overall functional behavior to prevent the hazard.

Option C, “The software shall implement a plausibility check for throttle pedal position,” is a specific design or implementation detail, not a top-level functional safety requirement. While it might contribute to fulfilling a functional safety requirement, it is too granular.

Option D, “The vehicle shall comply with Euro NCAP safety standards,” refers to an external regulatory or testing framework and does not define a specific safety function to mitigate the identified hazard.

Therefore, the functional safety requirement that directly supports the safety goal of preventing unintended acceleration from causing a collision is the one that specifies the functional behavior of detection and mitigation within a defined timeframe.