SOFTWARE FAILURE MODE AND EFFECT ANALYSIS (SFMEA) - Software Design for Six-Sigma: A Roadmap for Excellence - page 417

TABLE 16.2 (Continued)

Year Reference Contribution

or system loss. Critical failures are failures
that may cause severe injury or major system
damage that result in mission loss. Marginal
failures are failures that may cause minor
injury or minor system damage that results in
delay or loss of availability or mission
degradation. Minor failures are not serious
enough to cause injuries or system damage but
result in unscheduled maintenance or repair.

Maier, T., FMEA and FTA to
support Safe Design of
Embedded software in
Safety-Critical Systems.
Safety and Reliability of
Software Based Systems,
Twelfth Annual CSR
Workshop, pp. 351-367,
1997.

Maier:
Described the use of FMEA during the
development of robot control system software
for a fusion reactor.
Used FMEA to examine each software
requirement for all possible failure modes.
Failure modes included an unsent message, a
message sent too early, a message sent too late,
a wrong message, and a faulty message.
FMEA causes included software failures,
design errors, and unforeseen external events.
Noted that for software failures, additional
protective functions to be integrated in the
software may need to be defined. For design
errors, the errors may need to be removed, or
the design may need to be modified.
Stated that unforeseen external events may be
eliminated by protective measures or by
changing the design.
Recommended that the methodology he
presented be applied at an early stage of the
software development process to focus
development and testing efforts.

Pries, K.H., Failure Mode
and Effects Analysis in
Software Development, SAE
Technical Paper Series No.
982816, Warrendale, PA,
Society of Automotive
Engineers, 1998.

Pries:
Outlined a procedure for using software design
FMEA.
Stated that software design FMEA should start
with system or subsystem outputs listed in the
item and function (left-most) columns of the
FMEA. The next steps are to list potential
failure modes, effects of failures, and potential
causes.

1998

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