SOFTWARE QUALITY CONCEPTS - Software Design for Six-Sigma: A Roadmap for Excellence - page 7

TABLE 1.1 Shows Some Standard Organizations

Organization Notes

ANSI American National Standards Institute (does not itself make

standards but approves them)

AIAA American Institute of Aeronautics and Astronautics

EIA Electronic Industries Association

IEC International Electro technical Commission

IEEE Institute of Electrical and Electronics Engineers Computer

Society Software Engineering Standards Committee

ISO International Organization for Standardization

1997). Most software engineers learn the skills they need on the job, and this is not only
expensive and time consuming, but also it is risky and produces low-quality products.
The work of software engineers has not changed a lot during the past 30 years
(Watts, 1997) even though the computer field has gone through many technological
advances. Software engineers uses the concept of modular design. They spend a large
portion of their time trying to get these modules to run some tests. Then they test
and integrate them with other modules into a large system. The process of integrating
and testing is almost totally devoted to finding and fixing more defects. Once the
software product is deployed, then the software engineers spend more time fixing the
defects reported by the customers. These practices are time consuming, costly, and
retroactive in contrast to DFSS. A principle of DFSS quality is to build the product
right the first time.
The most important factor in software quality is the personal commitment of the
software engineer to developing a quality product (Watts, 1997). The DFSS process
can produce quality software systems through the use of effective quality and design
methods such as axiomatic design, design for X, and robust design, to name few.
The quality of a software system is governed by the quality of its components.
Continuing with our fuzzy formulation (Figure 1.1), the overall quality of a software
system ( µ Quality) can be defined as

µ Quality = min( µ Q 1 ,µ Q 2 ,µ Q 3 ,...µ Qn )

where µ Q1, µ Q2, µ Q3, ... , µ Qn are the quality of the n parts (modules) that makes up

the software system, which can be assured by the QA function.
QA includes the reviewing, auditing, and reporting processes of the software
product. The goal of quality assurance is to provide management (Pressman, 1997)
with the data needed to inform them about the product quality so that the man-
agement can control and monitor a product's quality. Quality assurance does apply
throughout a software design process. For example, if the water fall software design
process is followed, then QA would be included in all the design phases (require-
ments and analysis, design, implementation, testing, and documentation). QA will be
included in the requirement and analysis phase through reviewing the functional and