Page 322 - Design for Six Sigma a Roadmap for Product Development

292 Chapter Nine

■ Knowledge on all available fields (field properties, utilizations,
etc.)
■ Past knowledge
■ Other people’s knowledge
■ Knowledge on operation
6. Functional resources:
■ Unutilized or underutilized existing system main functions
■ Unutilized or underutilized existing system secondary functions
■ Unutilized or underutilized existing system harmful functions

In TRIZ, it is more important to look into cheap, ready-to-use, abundant
resources rather than expensive, hard-to-use, and scarce resources.
Here is an example.

Example 9.2. Cultivating Fish in Farmland The southeastern part of China
is densely populated, so land is a scarce resource. Much of the land is used
to plant rice. Agriculture experts suggest that farmland can be used to cul-
tivate fish while the land is used to grow rice, because in rice paddies
water is a free and ready resource, and fish waste can be used as a fertil-
izer for rice.

9.2.3 Ideality
Ideality is a measure of excellence. In TRIZ, ideality is defined by the
following ratio:

∑ benefits
Ideality (9.1)
∑ costs ∑ harm

where ∑ benefits sum of the values of system’s useful functions.
(Here the supporting functions are not consid-
ered to be useful functions, because they will not
bring benefits to customers directly. We consider
supporting functions are part of the costs to make
the system work.)
∑ costs sum of the expenses for system’s performance
∑ harm sum of “harms” created by harmful functions
In Eq. (9.1), a higher ratio indicates a higher ideality. When a new
system is able to achieve a higher ratio than the old system, we con-
sider it a real improvement. In TRIZ, there is a “law of increasing
ideality,” which states that the evolution of all technical system
proceeds in the direction of increasing degree of ideality. The ideality
of the system will increase in the following cases: