Page 262 - Design for Six Sigma for Service (Six SIGMA Operational Methods)

Theory of Inventive Problem Solving (TRIZ) 231

Evaluation
In any engineering project, we need to evaluate the soundness of the new
solution. TRIZ has its own evaluation approach. However, other non-TRIZ
methods might also be used at this stage, such as axiomatic design and
design vulnerability analysis.

In subsequent sections, we first discuss the philosophical aspects of TRIZ in
order to lay a foundation for understanding. Then we discuss the four-step TRIZ
problem definition and solving process, together with the tools used in TRIZ.

9.2 TRIZ Fundamentals

Ideality, functionality, contradictions, use of resources, and evolution are
the pillars of TRIZ. These elements make TRIZ distinctively different from
other innovation and problem-solving strategies. In this section, we describe
all five elements.

9.2.1 Function Modeling and Functional Analysis

Function modeling and functional analysis originated in value engineering
(Miles 1961). A function is defined as the natural or characteristic action
performed by a product or service. Usually, a product or service provides
many functions. For example, an automobile provides customers with the
ability to get from point A to point B, with a comfortable riding envi-
ronment, air conditioning, music, and so on.

Among all functions, the most important is called the main basic function.
It is defined as the primary purpose or the most important action performed
by a product or service. The main basic function must always exist, although
methods or designs to achieve it may vary. For example, for an automobile,
the ability to get from point A to B is the main basic function.

Besides the main basic function, there are other useful functions as well; we
can call these secondary useful functions. There are several kinds of
secondary useful functions:
1. Secondary basic functions: These are not main basic functions, but
customers definitely need them. For example, providing a comfortable
riding environment is a must-have function for automobiles.
2. Nonbasic but beneficial functions: These are functions that provide
customers with esteem value, comfort, and so on. For example, the
paint finish on an automobile provides both basic and nonbasic