INTRODUCTION TO SOFTWARE DESIGN FOR SIX SIGMA (DFSS) - Software Design for Six-Sigma: A Roadmap for Excellence - page 179

to put the summary in a matrix called the morphological matrix. 6 An overall design
alternative set is synthesized from this matrix that is conceptually high-potential and
feasible solutions. Which solution should they choose? The Pugh matrix, a concept
selection tool named after Stuart Pugh, can be used. The selected solution will be
subjected to a thorough design optimization stage (stage 5). This optimization could
be deterministic and/or statistical in nature. On the statistical front, the design solution
will be made insensitive to uncontrollable factors (called the noise factors) that may
affect its performance. Factors like customer usage profile and use environment
should be considered as noise. To assist on this noise insensitivity task, we rely on the
transfer function as an appropriate vehicle. In stage 5, the team needs to make detailed
documentation of the optimized solution. This documentation must include all of the
information needed to produce the software. Consideration for design documentation,
process maps, operational instructions, software code, communication, marketing,
and so on should be put in place. In stage 6, the team can make a model assuming
the availability of the transfer functions and later a prototype or they can go directly
to making a prototype or a pilot. A model is a full-size or small-scale simulation.
Architects, engineers, and most designers use models. Models are one more step in
communicating the functionality of the solution. A scale model is used when design
scope is very large. A prototype is the first working version of the team's solution.
Design verification and validation, stage 6, also includes testing and evaluation, which
is basically an effort to answer these very basic questions: Does it work? (Does it
meet the design charter? If failures are discovered, will modifications improve the
solution?) These questions have to be answered. After having satisfactory answers,
the team can move to the next development and design stage.
In stage 7, the team needs to prepare the production facilities where the software
will be produced for launch. At this stage, they should ensure that the software
is marketable and that no competitors beat them to the market. The team together
with the project stakeholders must decide how many to make. Similar to products,
software may be mass-produced in low volume or high volume. The task of making
the software is divided into jobs. Each worker trains to do his or her assigned job. As
workers complete their special jobs, the software product takes shape. Post stage 7,
the mass production saves time and other resources. Because workers train to do a
certain job, each becomes skilled in that job.
8.5 SOFTWARE DFSS: THE ICOV PROCESS IN
SOFTWARE DEVELOPMENT
Because software DFSS integrates well with a software life-cycle system, it is an
event-driven process, in particular, the development (design) stage. In this stage,
milestones occur when the entrance criteria (inputs) are satisfied. At these milestones,
the stakeholders including the project champion, design owner, and deployment
6 A morphological matrix is a way to show all functions and corresponding possible design parameters
(solutions).