Page 355 - Design for Six Sigma a Roadmap for Product Development

Theory of Inventive Problem Solving (TRIZ) 325

Example 9.23. Lightning Rod A lightning rod draws off thunderstorm-
induced electrical shock from the building.
Example 9.24. Protecting Underground Cables
Old design

Cable
Cable (2)
1 2

Crack Earth Earth (1)

A cable is buried in the soil. [Disadvantage: Cracks in the earth (due to hard
frost) can damage the cable.]
New design

Trench Cable Trench Cable (2)

1 2

Earth Earth (1)
Crack

It is proposed to dig trenches in the earth parallel to the cable. These attract
the frost-heaving cracks, keeping the cable undamaged.

Method 4:Trim or replace the subject of a
harmful function
We can trim or replace the subject of the harmful function by one of the
following ways in order to make the subject not create a harmful action
(see Sec. 9.7):
■ Simplify the system so the subject is eliminated (see Sec. 9.7).
■ Replace the subject by another part of the system.