Page 326 - Design for Six Sigma a Roadmap for Product Development

296 Chapter Nine

Brush
Toothbrush Teeth
Mech.

If that is the case, it belongs to the problem of “inadequate functional
performance,” and we can use the TRIZ standard solution technique to
resolve this problem.
2. We may find the current functional model is too limiting, because the
function statement “toothbrush brushes teeth” limits our solution to
using the brush only and to using mechanical action only. We can develop
the following alternative functional modeling:

Tooth cleaning Remove
device Dirt in teeth

The subject “toothbrush” is replaced by a more general “tooth cleaning
device.” The object “teeth” is changed to “dirt in teeth,” which is more
precise. The action “brush” is changed to a more general term “remove.”
Under this alternative functional modeling, many possible choices of
“subjects” and “actions” can be open for selection. For example, we can use
hydraulic action to clean teeth, or chemical action to clean teeth, we can
even consider pretreatment of teeth to make them dirt free and so on.
Clearly this alternative functional modeling opens the door for problem
solving and innovation.

Ideality and ideal final result. After functional modeling and functional
analysis, we can evaluate the ideality of the current system by using

∑ benefits
Ideality
∑ costs ∑ harm

Ideal final result means the ultimate optimal solution for current
system in which:
∑ benefits → and ∑ costs ∑ harm → 0

By comparing the ideality of the current system with ideal final
result, we can identify “where the system improvement should go”
and “what aspects of system should be improved.” This will definitely
help the problem definition and identify “what problem should be
solved.”

S-curve analysis. It is very beneficial to evaluate the evolution stage of
the current technical system involved in any TRIZ project. For exam-
ple, if our current subsystem is at the growth stage, then we should
focus our attention to gradual improvement. If our subsystem is near