Page 180 - Design for Six Sigma for Service (Six SIGMA Operational Methods)

152 Chapter Seven

At the top of Fig. 7.2, a why-how arrow tells the relationships among these four
functions. To modify behavior, you have to do all three functions, eliminate
deviancy, identify needs, and assist clients. Why do we need to perform these
three functions? Because we want to modify behavior.
In a similar manner, we can expand Fig. 7.2 by adding more functions, as
illustrated by Fig. 7.3. Again, the function on the left gives the reason why the
functions on the right should be performed, and the functions on the right tell
how the function on the left can be accomplished. For example, the function to
the right of “eliminate deviancy” is “plan activities”; the function to the right of
“plan activities” is “determine needs.” Why do we plan activities? Because we
want to eliminate deviancy. Why do we determine needs? Because we want to
plan activities. How do we eliminate deviancy? By planning activities! How do
we plan activities? By determining needs!

Now we are ready to go over the details about establishing the FAST
diagram for a value-engineering project. The general format of a FAST
diagram is illustrated in Fig. 7.4.

We now define the terminologies used in the FAST diagram.

Scope of the Project The scope of the project is depicted as two vertical
dotted lines. The scope lines bound the project under study or a portion
of the problem with which the study team is concerned.
Highest-Order Function(s) The objective or output of the basic
function(s) and subject under study is referred to as the highest-order
function(s); it appears outside the left scope line and to the left of the
basic function(s). Any function to the left of another on the primary
path is a higher-order function.

How Why

Eliminate Plan Determine
deviancy activities needs

Modify Identify Define Plan
behavior needs problems treatment

Assist Improve
client process

Figure 7.3 Part of FAST Diagram for Youth Assistance Program