Page 365 - Design for Six Sigma a Roadmap for Product Development

Theory of Inventive Problem Solving (TRIZ) 335

Techniques to increase benefits

Increasing the number of functions in a single system. This is featured by
mono-bi-poly evolution. Mono means monosystem. A monosystem
is defined as a single object having one function. Examples are as
follows:

■ A knife
■ A one-barrel hunting rifle
Bi means bisystem. A bisystem is defined as the combination of two
subsystems whose functions could be identical, similar, different, or
even opposite. Here are some examples of bisystems:

■ A two-barreled hunting rifle, which is a combination of two mono-
barreled rifles.
■ A straight/Phillips screw driver. One tip is straight and the other is
Phillips. It is a combination of two similar functions.
■ Wristwatch calculator. It is a combination of a watch and calculator,
a combination of different functions.
■ A pencil with eraser. A combination of two opposite functions.

Poly means a polysystem. A polysystem is defined as the combina-
tion of three or more subsystems whose functions are identical, simi-
lar, different, or even opposite. The examples of a polysystem include
multiple stage rocket, Swiss army knife and power tool sets, sound sys-
tem (a combination of radio, CD player, tape player, etc).
Mono-bi-poly evolution states that the development of a technologi-
cal system is often featured by adding more and more functions, from
a simple monosystem, to a bisystem, and to a poly system.
Increasing the magnitude and quality of a function. In the evolution of tech-
nological systems, not only are the number of functions likely to
increase, but also the magnitude and quality of functions improve. For
example, in the development of a firearm, the early generation of a
fire-arm could only shoot at short distance, and was not very powerful,
with very low frequency and poor accuracy. As the technology develops,
it can shoot further and further, and it becomes more and more power-
ful, with higher and higher frequency and accuracy.

Example 9.31. OneCard System of a University The students of a univer-
sity used to carry many cards, including a health club card, a library card,
and a parking card. The university administration developed a OneCard
system in which all the information is stored in one plastic card on the
same magnetic strip. By using this card, a student can enter any facility,