SIX SIGMA FUNDAMENTALS - Software Design for Six-Sigma: A Roadmap for Excellence - page 168

Lower specification limit Upper specification limit

Oct 99

Oct 01

− 25 0 25 50

Schedule slippage (%)

FIGURE 7.16 Process capability analysis for schedule slippage (Muruguppan & Keeni,

2003).

Monitoring of software project schedules as part of the software development
cycle is another aspect where Six Sigma methodology has been used, as shown in
Figure 7.16. During a two-year period, the company claims to have reduced the
variation (sigma) associated with slippage on project schedules making its customer
commitments more consistent. This claim could be a murky one because the study
does not indicate how many projects were delivered during the timeframe and how
many projects were similar. These factors could alter the conclusion as Six-Sigma-
based statistics requires a sufficient sample size for results to be meaningful.
In addition, this there are other instances where the Six Sigma technology has
been applied effectively to the software development cycle. Although Six Sigma
continued to be practiced in manufacturing as a way to optimize processes, its use in
the software development cycle, particularly in the area of problem solving, seems
to have gained traction since the late 1990s.

7.11 SIX SIGMA GOES UPSTREAM—DESIGN FOR SIX SIGMA

The Six Sigma DMAIC 5 (Define-Measure-Analyze-Improve-Control) methodology
is excellent when dealing with an existing process in which reaching the entitled
level of performance will provide all of the benefit required. Entitlement is the best
the process or product (including software) is capable of performing with adequate
control. Reviewing historical data it is often evident as the best performance point. But
what do we do if reaching entitlement is not enough or there is a need for an innovative
solution never before deployed? We could continue with the typical code it-build
it-fix it cycle, as some of the traditional software development processes promote
in this chapter, or we can use the most powerful tools and methods available for
developing an optimized, robust, derisked software design. These tools and methods
can be aligned with an existing new software development process or used in a
stand-alone manner.

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