SOFTWARE QUALITY FUNCTION DEPLOYMENT - Software Design for Six-Sigma: A Roadmap for Excellence - page 317

Strong 9

Moderate 3

Weak 1

FIGURE 12.5 Rating values for affinities.

Next we move to Room #2 and compare our performance and the competitions'
performance against these “Whats” in the eyes of the customer. This is usually
a subjective measure and is generally scaled from 1 to 5. A different symbol is
assigned to the different providers so that a graphical representation is depicted in
Room #2. Next we must populate Room #3 with the “Hows,” For each “What” in
Room #1, we ask “How can we fulfill this?” We also indicate which direction the
improvement is required to satisfy the “What”—maximize, minimize, or on target.
This classification is in alignment with robustness methodology (Chapter 18) and
indicates an optimization direction.
In HOQ1, these become “How does the customer measure the What?” In HOQ1,
we call these CTS measures. In HOQ2, the “Hows” are measurable and are solution-
free functions required to fulfill the “Whats” of CTSs. In HOQ3, the “Hows” become
DPs and in HOQ4 the Hows become PVs. A word of caution: Teams involved in
designing new softwares or processes often jump to specific solutions in HOQ1. It
is a challenge to stay solution-free until HOQ3. There are some rare circumstances
in which the VOC is a specific function that flows straight through each house
unchanged.
Within Room #4, we assign the weight of the relationship between each “What”
and each “How,” using 9 for strong, 3 for moderate, and 1 for weak. In the actual
HOQ, these weightings will be depicted with graphical symbols, the most common
being the solid circle for strong, an open circle for moderate and a triangle for weak
(Figure 12.5).
Once the relationship assignment is completed, by evaluating the relationship of
every “What” to every “How,” then the calculated importance can be derived by
multiplying the weight of the relationship and the importance of the “What” and
summing for each “How.” This is the number in Room #5. For each of the “Hows,”
a company also can derive quantifiable benchmark measures of the competition and
itself in the eyes of industry experts; this is what goes in Room #6. In Room #7, we
can state the targets and limits of each of the “Hows.” Finally, in Room #8, often
called the roof, we assess the interrelationship of the “Hows” to each other. If we
were to maximize one of the “Hows,” then what happens to the other “Hows”? If
it also were to improve in measure, then we classify it as a synergy, whereas if it
were to move away from the direction of improvement then it would be classified
as a compromise. In another example, “easy to learn” is highly correlated to “time
to complete tutorial” (a high correlation may receive a score of 9 in the correlation
matrix) but not “does landscape printing” (which would receive a score of 0 in the