SOFTWARE DESIGN FOR X - Software Design for Six-Sigma: A Roadmap for Excellence - page 378

of defining and validating all system test cases as part of a low-level design review is
achievable. 19
In this ICOV DFSS phase, team predesign review meetings provide members with
forums to expand their knowledge base of DFSS design techniques by exchanging
design templates. Design review results will be greatly improved if they are preceded
by brief, informal reviews that are highly interactive at multiple points throughout the
progression from system architecture through low-level design. Prior to the final stage
of this phase, software failure analysis is used to identify core and vulnerable sections
of the software that may benefit from additional runtime protection by incorporating
software fault-tolerance techniques. The major activities in this phase are:
Inclusion of DFR in team design reviews
Software failure analysis
Software fault tolerance
14.2.4.3 DFSS Optimize Phase DFR Practices. Code reviews should be
carried out in stages to remove the most defects. Properly focused design reviews
coupled with techniques to detect simple coding defects will result in shorter code
reviews. Code reviews should focus on implementation issues and not design issues.
Language defects can be detected with static and with dynamic analysis tools.
Maintenance defects that are caught with coding standards prereviews in which
authors review their own code significantly reduces simple code defects and possible
areas of code complexity. The inspection portion of a review tries to identify missing
exception handling points. Software failure analysis will focus on the robustness of
the exception handling behavior. Software failure analysis should be performed as a
separate code inspection once the code has undergone initial testing.
In this ICOV DFSS phase, reliability reviews target only the core and vulnerable
sections of code to allow the owner of the source code to develop sufficient synergy
with a small team of developers in finding defects. Unit testing efforts focus on
efficient detection of software faults using robustness and coverage testing techniques
for thorough module-level testing. The major activities in this phase are:
Code reliability reviews
Software robustness (Chapter 18)
Coverage testing techniques
14.2.4.4 DFSSVerifyandValidatePhaseDFRPractices. Unit testing can
be driven effectively using code coverage techniques. It allows software belts to de-
fine and execute unit testing adequacy requirements in a manner that is meaningful
and easily measured. Coverage requirements can vary based on the critical nature of
19 See Silverman and De La Fuente, http://www.opsalacarte.com/pdfs/Tech Papers/Software Design for
Reliability - Paper.pdf.