SOFTWARE QUALITY FUNCTION DEPLOYMENT - Software Design for Six-Sigma: A Roadmap for Excellence - page 322

Applications

Engineering Measures

Requirements / Use-Cases

1 Translating I/O to and from

database protocols

S 4 3 9

2 Adding and removing interfaces

S
S

5
6
2.5
3.5
3.5

9

Applications 3 Verifying data content and integrity

9

4
5

Optimizing routing
Managing exceptions en route

D 99

9

S 3

6 Logging performance data 3

D

FIGURE 12.8 HOQ 2 VOCs translation to CTSs. 1

may be converted to multiple technical product specifications, making it crucial to
have extensive user involvement. Additionally, the technical product specifications
must be measurable in some form. The metrics used are usually numerically based
but also may be Boolean. For example, the customer requirement “provides multiple
print formats” may be converted to “number of print formats” (using a numerically
based metric) and “does landscape printing” (measured using “Yes” or “No”).
The CTSs list is the set of metrics derived by the design team from the customer to
answer the customer attributes list. The CTSs list rotates into HOQ 2 Room #1 in this
QFD phase. The objective is to determine a set of functional requirements (FRs), with
which the CTSs requirements can be materialized. The answering activity translates
customer expectations into requirements such as waiting time, number of mouse
clicks for online purchasing service, and so on. For each CTS, there should be one or
more FRs, that describe a means of attaining customer satisfaction. A QFD translation
example is given in Figure 12.8. A complete QFD example is depicted in Figure 12.9.
At this stage, only overall CTSs that can be measured and controlled need to be
used. We will call these CTSs, technical CTSs. As explained earlier, CTSs are tradi-
tionally known as substitute quality characteristics. Relationships between technical
CTSs and FRs often are used to prioritize CTSs filling the relationship matrix of
HOQ2 rooms. For each CTS, the design team has to assign a value that reflects the
extent to which the defined FRs contribute to meeting it. This value, along with the

1 Hallowell, D. on http://software.isixsigma.com/library/content/c040707b.asp.