FMEA¶

The FMEA is done at the “General” and “Use-Case” level of the library architecture. The “Use cases” chapter was analyzed over:

Fault Model¶

The following model is based on the “SWA Fault Model” for activity diagrams currently used for embedded software.

Element Type	Error ID	Generic Error Description
Data storage	DS1	Stored data changed before read operation
	DS2	New data not stored / keeps old data / stuck at specific value
Data flow	DF1	Transferred data changed
	DF2	Transferred data lost
	DF3	Data stored at / read from wrong location in data store
	DF4	Data transferred to wrong data store
Processing	PR1	Calculates wrong results
	PR2	Processing is skipped
	PR3	Processing too slow / fast
Control flow	CF1	Control flow stops
	CF2	Control flow proceeds to wrong process

If more than one error is identified for the same element with the same error ID, a counter is added, e.g. DF1.1, DF1.2, etc.

The following errors are analyzed generically and not on architectural element level.

Error ID	Affected Elements	General Error Description	Measures
DF2	Data flow from / to shell and internal data storage.	Internal buffers data lost	Single thread library
PR3	Processing	Timing issue on slow execution leading to timeouts expiration, low efficiency in execution time	Coding style / Code review Reduced cyclomatic complexity Sleep in the code not normally allowed Minimum strictly needed inclusions are used
CF1	Control flow	Blocking methods without timeout coverage, Ruby VM stuck on non retuning forks leading to execution stuck, low efficency in execution time	Coding style / Code review Cover blocking calls with timeouts

The analysis for this section was done based on the Explore part of the use cases diagram in the use cases session

Element	Error ID	Specific Error Description	Measures	References
Explorer	DS2 / DF3 / DF4	User configuration (`.dragnet.yaml`) is malformed / not supported encoding leading to parsing error or wrong initial configuration. i.e. the configuration may be generated or transferred leading to loss of integrity.	Assumption for the library user on performing integrity check over user configuration before using in the library. The integrity has to be granted also in the case the configuration file is generated or given to the Library by any script. Code Testing grant coverage over exceptions handling

The analysis for this section was done based on the Validate part of the use cases diagram in the use cases session

Element	Error ID	Specific Error Description	Measures	References
Validator	DS2 / DF3 / DF4	MTRs configurations content is malformed / not supported encoding leading to parsing error or wrong initial configuration. i.e. the configuration may be generated or transferred leading to loss of integrity.	Assumption for the library user on performing integrity check over user configuration before using in the library. The integrity has to be granted also in the case the configuration file is generated or given to the Library by any script. Code Testing grant coverage over exceptions handling

The analysis for this section was done based on the Verify part of the use cases diagram in the use cases session

Element	Error ID	Specific Error Description	Measures
Verifier, ChangesVerifier, Repository	PR1	Library to Git passed parameters wrong / malformed leading to wrong behaviour	Code review
Master	PR1.1	Library fails to handle internal exceptions leading to wrong behaviour	Code review, unit / integration testing
Verifier, ChangesVerifier, Repository	PR2	Git connection loss leading to wrong behaviour	Code review over exception coverage
Logger	PR1	Library to CLI passed data is wrong / malformed leading to wrong behaviour	Code review

The analysis for this section was done based on the Export part of the use cases diagram in the use cases session

Element	Error ID	Specific Error Description	Measures	References
Exporter, HTMLExporter, JSONExporter	PR1	Library to JSON/HTML export data passed is wrong / malformed leading to wrong behaviour	Code review