DFA failure initiators#

DFA failure initiators		status: valid
tags: safety_analysis, safety_analysis contained by: wf__analyse_platform_featarch, wf__analyse_featarch, wf__analyse_comparch, wf__mr_saf_analyses_dfa, wf__vy_saf_analyses_dfa complies: std_req__iso26262__software_7411, std_req__iso26262__analysis_744, std_req__iso26262__software_748, std_req__iso26262__software_749

gd_guidl__dfa_failure_initiators		Process Guideline

Note

Use all applicable failure initiators to ensure a structured analysis. If there are additional failure initiators needed, please enlarge the list of fault models.

Note

An ASIL related message is trustable in that manner that it is not corrupted, repeated, lost, delayed, masqueraded or addressed incorrectly.

Purpose

In order to identify all cascading and common cause failures, which may initiated from your feature or components to the platform, other features, components, etc., use the following framework of dependent failure initiators to check your completeness of the analysis.

DFA failure initiators#

Shared resources#

Note

Shared libraries are only than to be considered as a shared resource if the feature and the related safety mechanisms are using this specific library. If the library is not used by the feature or the related safety mechanisms, it is not a shared resource.

ID	Failure Mode	Importance
dfa_failure_initiator__sr_01_01	Reused software components	Medium
dfa_failure_initiator__sr_01_02	Libraries	Medium
dfa_failure_initiator__sr_01_04	Basic software	Medium
dfa_failure_initiator__sr_01_05	Operating system including scheduler	Medium
dfa_failure_initiator__sr_01_06	Any service stack, e.g. communication stack	Medium
dfa_failure_initiator__sr_01_07	Configuration data	Medium
dfa_failure_initiator__sr_01_09	Execution time	Medium
dfa_failure_initiator__sr_01_10	Allocated memory	Medium

Communication between elements#

Receiving function is affected by information that is false, lost, sent multiple times, or in the wrong order etc. from the sender.

ID	Failure Mode	Importance
dfa_failure_initiator__co_01_01	Information passed via argument through a function call, or via writing/reading a variable being global to the two software functions (data flow)	Medium
dfa_failure_initiator__co_01_02	Data or message corruption / repetition / loss / delay / masquerading or incorrect addressing of information	Medium
dfa_failure_initiator__co_01_03	Insertion / sequence of information	Medium
dfa_failure_initiator__co_01_04	Corruption of information, inconsistent data	Medium
dfa_failure_initiator__co_01_05	Asymmetric information sent from a sender to multiple receivers, so that not all defined receivers have the same information	Medium
dfa_failure_initiator__co_01_06	Information from a sender received by only a subset of the receivers	Medium
dfa_failure_initiator__co_01_07	Blocking access to a communication channel	Medium

Shared information inputs#

Same information input used by multiple functions.

ID	Failure Mode	Importance
dfa_failure_initiator__si_01_02	Configuration data	Medium
dfa_failure_initiator__si_01_03	Constants, or variables, being global to the two software functions	Medium
dfa_failure_initiator__si_01_04	Basic software passes data (read from hardware register and converted into logical information) to two applications software functions	Medium
dfa_failure_initiator__si_01_05	Data / function parameter arguments / messages delivered by software function to more than one other function	Medium

Unintended impact#

Unintended impacts to function due to various failures.

ID	Failure Mode	Importance
dfa_failure_initiator__ui_01_01	Memory miss-allocation and leaks	Medium
dfa_failure_initiator__ui_01_02	Read/Write access to memory allocated to another software element	Medium
dfa_failure_initiator__ui_01_03	Stack/Buffer under-/overflow	Medium
dfa_failure_initiator__ui_01_04	Deadlocks	Medium
dfa_failure_initiator__ui_01_05	Livelocks	Medium
dfa_failure_initiator__ui_01_06	Blocking of execution	Medium
dfa_failure_initiator__ui_01_07	Incorrect allocation of execution time	Medium
dfa_failure_initiator__ui_01_08	Incorrect execution flow	Medium
dfa_failure_initiator__ui_01_09	Incorrect synchronization between software elements	Medium
dfa_failure_initiator__ui_01_10	CPU time depletion	Medium
dfa_failure_initiator__ui_01_11	Memory depletion	Medium
dfa_failure_initiator__ui_01_12	Other HW unavailability	Medium

Development failure initiators#

Section is only applicable if a divers SW development is needed due to decomposition.

Note

Section shall be applied only once to analyse all dependencies of the features. Results shall be checked during of the analysis of new features if this is applicable to the feature.

ID	Failure Mode	Importance
dfa_failure_initiator__sc_01_02	Same development approaches (e.g. IDE, programming and/or modelling language)	Medium
dfa_failure_initiator__sc_01_03	Same personal	Medium
dfa_failure_initiator__sc_01_04	Same social-cultural context (even if different personnel). Only applicable if diverse development is needed.	Medium
dfa_failure_initiator__sc_01_05	Development fault (e.g. human error, insufficient qualification, insufficient methods). Only applicable if diverse development is needed.	Medium