Creating a FAST Model

The FAST model has a horizontal directional orientation described as the how-why dimension. This dimension is described in this manner because how and why questions are raised to structure the logic of the system’s functions. Starting with how a function is performed, helps in developing a more specific approach. This line of questioning and thinking is read from left to right (see Figure 7.3).

To abstract the problem to a higher level, why questions are raised and are read from right to left. First, the best way to undertake a task is to begin with the goals of the task, then going back to exploring the methods to attain the goals. When the FAST model is used to address any function with the question why, the function to its left expresses the goal of that function. The question how, is resolved by the function on the right, and is a method to perform that function being addressed. A systems diagram starts at the beginning of the system and ends with its goal (see Figure 7.3). A FAST model, reading from left to right, starts with the goal, and ends at the beginning of the

“system” that will achieve that goal.

Second, changing a function on the how-why path affects all of the functions to the right of that function. This is a domino effect that only goes one way, from left to right.

Starting with any place on the FAST model, if a function is changed the goals are still valid (functions to the left), but the method to accomplish that function, and all other functions on the right, will be affected.

Finally, building the model in the how direction, or function justification, will focus the attention on each function element of the model (see Figure 7.4). Whereas, reversing the FAST model and building it in its system orientation will cause the team to leap over individual functions and focus on the system, leaving function “gaps” in the system. One rule to remember is while constructing a FAST model build in the how

Figure 7.6 We expand our analysis of the counseling activity.

direction also test the logic in the why direction (see Figure 7.1 and Figure 7.6).

The vertical orientation of the FAST model is described as the when direction. This is not part of the intuitive logic process, but enhances the intuitive thinking process.

We should note that when indicates cause and effect and does not represent time orientation.

Boundaries of the study are represented by the scope lines and are visible as two vertical lines on the FAST model. The scope lines bound the “scope of the study,”

or that aspect of the problem with which the study team is concerned. The left scope line determines the basic function(s) of the study. The basic functions will always be the first functions to the immediate right of the left scope line. The right scope line identifies the beginning of the study and separates the input function(s from the scope of the study.

The objective or goal of the study is the “highest order function,” located to the left of the basic function(s and outside of the left scope line. Any function to the left of another function is a “higher order function.” Functions to the right and outside of the right scope line represent the input side that “turn on” or initiate the subject under study and are known as lowest order functions. Any function to the right of another function is a “lower order” function and represents a method selected to carry out the function being addressed.

Functions that are to the immediate right of the left scope line represent the purpose or mission of the product or process under study and are called “basic functions.” The basic function will not change once it has been determined. If the basic function fails, the product or process will lose its market value. All functions to the right of the basic functions portray the conceptual approach selected to satisfy the basic function.

The concept describes the method being considered, or elected, to achieve the basic function(s).

The concept either represents the current conditions (as is) or proposed approach (to be). It is always good to create a “to be” rather than an “as is” FAST model, even if the assignment is to improve an existing product. The “to-be” approach provides Figure 7.7 We continue our development of the prototype FAST diagram.

an opportunity to compare the ideal product to the current product, and thus resolves questions on how to implement the differences.

An “as is” model will limit the team’s attention to incremental improvement opportunities. To trace the symptoms of a problem to its root cause and to explore the ways to resolve a problem, an “as is” model is extremely useful. It is useful because of the dependent relationship of functions that form the FAST model.

Any function on the how-why logic path is a logic path function. If the functions along the why direction lead into the basic functions, then they are located on the major logic path. If the why path does not lead directly to the basic function, it is a minor logic path.

Changing a function on the major logic path will alter or destroy the way the basic function is performed. Changing a function on a minor logic path will disturb an independent (supporting) function that enhances the basic function. Supporting functions are usually secondary and exist to achieve the performance levels specified in the objectives or specifications of the basic functions or because a particular approach was chosen to implement the basic functions.

Independent functions describe enhancements of a function located on the logic path. They do not depend on another function selected to perform that function.

Independent functions are located above the logic path function(s), and are considered secondary, with respect to the scope, nature, level of the problem, and its logic path.

Figure 7.8 The process becomes a little easier once we have some practice converting to verb–noun statements.

students

Figure 7.9 Our FAST diagram thus far.

Let’s take a look at our “school counselor” example. We will walk through the stages of developing the FAST diagram as well as adding some commentary to make it clear why we made the decisions we made. Our first step is to define the highest order function, which we consider to be “champion students.” All other functions will be subordinate to this high order function.

We can take a hint for the next step by looking at the American School Counselor Association (ASCA) national model, with some minor modifications:

In Figure 7.4, we added the Snodgrass-style supporting functions to the basic functions, which in turn, are subordinate to the high-order function. What we have is some difficulty aligning the counseling concepts as we understand them with the standard Snodgrass nomenclature. We would like to note that we are using the ASCA Standard National Model as a basis for our example and any failures in interpretation belong to us! We have changed some of the wording to reflect the demand for the verb–noun approach.

The noun–verb requirement cramps our style, as well it should. The entire purpose of this approach is to flush out the fluffy language often used in ambiguous descriptions.

Do not take this comment as a condemnation of the national standard. We are building a FAST model, not critiquing the ASCA model!

Using the verb–noun format and endeavoring to eliminate ambiguity is a huge component of the FAST effort. These actions are very similar to the difficulties we run into when writing a requirements specification (if we are the writer) and deciphering the requirement specification (if we are the supplier or contractor). We think the exercise is worth the effort. The “verb–noun” approach was a major insight by Lawrence Miles and provides us with a tool and a filter for the removal of indeterminacy in our use of language.

The way we present this example is but one formulation of the FAST approach.

In some diagrams, we will see a critical path identified that takes off horizontally from the basic function. We are trying to avoid producing a simple hierarchy chart of supporting functions because that is not really what a FAST diagram is designed to be.

We will continue our analysis.

School counselors still provide career guidance to students, much as they did in the days when they were known as “vocational counselors.” Of course, term “vocational”

comes from the Latin word for “calling.”

We took the national model idea of social skills and came up with “develop community” which is not quite the same thing. However, we must align with the verb–

noun requirements and that is one way to do that.

In Figure 7.9, we can see how our diagram is developing. The next step will involve developing each box further to the right as we more carefully explicate the “how”

of each “why.” As we indicated, we are not building a hierarchy chart of derived behaviors. Consider for a moment the difficulty of the exercise. In this example, we are dealing with a topic that we see described most often in qualitative terms. We also see this in the verb–noun boxes we have developed so far. The ideal is to come up with nouns that we can measure; however, it may not always be the case that we can easily find a way to achieve measurable results. We should have no bias towards qualitative data. One example of the benefits of qualitative approaches is the

Kastle-Meyer test for blood, which is an extremely quick test conducted with phenolphthalein and hydrogen peroxide and which only tells us whether the brown substance is blood or not. If not, we presumably waste no more time on the sample; if yes, we move on to the next step. We can construct our FAST diagrams, at least in part, with high-value qualitative information with no shame. Our goal is comprehension, especially in the case of cost reductions. We are not performing this exercise as some kind of religious ritual that allows for little or no latitude in performance. On the other hand, we do not want to completely obliterate the spirit of the technique. We recommend that the practitioner proceed with sound judgment and work through his or her own FAST diagram more than once and also submit it for review by peers and others.

If we take a look at Figure 7.10, we see the continuation of “optimize learning” as

we break that particular thread into components further defining the “how.” We can go as far to the right as makes sense until we reach some point, perhaps, where we have an “assumed” function. We really only cared about those functions we can derive as

“hows,” and in the other direction, those functions we can derive as “whys.”

What about our supporting functions? Figure 7.11 shows how we have expanded on the supporting functions recommended by Snodgrass. We think the expansion makes reasonable sense. Some FAST diagrams will never show much expansion of the supporting functions, but we think this approach adds more information and, hence, supplies value to the user. Office accessibility, feedback, training, and safe havens are items we can measure quantitatively. As we mentioned, a basic function dealing with self-development may have to use qualitative values. Either way, we learn more about our school counselor function.

We could continue this exercise to even deeper levels, but we suspect the example has presented most of what we need to know about FAST diagrams. The Snodgrass and Kasi book is available as of this writing at http://wendt.library.wisc.edu/miles/

milesvestudies.html. It is free to download and represents a complete analysis of how students

Figure 7.10 We begin to deepen our concepts.

Figure 7.11 We see in this figure how the supporting functions can be developed.

a standard FAST diagram would be constructed. We also recommend a free download of Lawrence Miles’s book Techniques of Value and Analysis and Engineering at http://

wendt.library.wisc.edu/miles/milesbook.html. The Miles book is more than 350 pages in length, and it contains many examples as well as Miles’s particular approaches to problem solving. Because of the soundness of the reasoning in both books, they remain current; they are also current because the ideas contained therein are timeless.

Additional papers by Miles and others can also be found at the Wendt library Web site at the University of Wisconsin at Madison. While other practitioners tout Six Sigma, Six Sigma Lean, and lean manufacturing (as do we), these works are exceptional in their clarity, logical thinking, well-ground methodologies, and power to effect financial improvement.

VI. EXERCISES

• Choose a sample product such as a pencil or a cupcake and develop a FAST diagram to represent this product. Present your results.

• Is the FAST approach too complicated for regular use by individuals without substantial training?

• Can we derive benefits from questioning why our product has certain features?

• The FAST approach is often used to achieve cost reductions by removing unnecessary or obsolete features. How would we use the FAST approach to add new features that may result in increased sales but do not really yield a cost reduction?

• Do the original design documents present any value for product analysis?

• Can we use the FAST technique with processes? Provide at last five example processes.

• In fact, can we use the FAST technique to analyze the FAST technique? Explain how this would be done and support your answer with an example.

• If the FAST technique is so good, why do not we use it all the time? In fact, why do we not use it during requirements analysis?

• How does FAST relate to regulatory requirements? If the FAST analysis indicates the regulatory requirement has no meaning, how would we handle this situation?

• How high a level can we use the FAST approach? For example, would we use it to analyze the purpose and costs of a battleship or an aircraft carrier?

• How low a level might we go to analyze a given product? Where do we stop?

Explain your criteria.

• Is the FAST technique itself sufficient documentation to implement a product change?

• If the FAST technique does not provide sufficient documentation to proceed with the change, what other documentation do we need?

• How do we maintain configuration management of a FAST analysis?

• Using the Internet, search for software tools that specifically support FAST analysis. Be prepared to produce a short presentation to your peers that describes the benefits and costs of using such a tool.

• If no tools available for FAST analysis, how would we convert an existing tool to support this methodology?

• We have seen the FAST technique used to support a more logical approach to the creation of a failure mode and effects analysis. How can we do this?

• How would we use FAST with Six Sigma, Lean Six Sigma, and lean manufacturing in a hybrid approach? Specify the phase or phases of these methodologies where we could use the FAST technique.

• Write a two-page essay describing how we might use FAST to improve the project management process.

• Is it possible to use FAST with controversial topics? For example, what would be the verb–noun substitute for the word “marriage?” How about “abortion?”

(Yes, these are emotional terms.) Can we remove the emotional overtones of any of these terms or are they so shrouded with position-taking, religious viewpoints and philosophy that we have no hope of ever coming to the table with some rational definitions?

ENDNOTES

1. Crow, Kenneth. “(1) Value Analysis and Function Analysis System Technique.”

New Product Development Solutions. Last modified 2002. Accessed November 23, 2011. http://www.npd-solutions.com/va.html.

2. Miles, Lawrence D. Techniques of Value Analysis and Engineering, 3rd Edition.

Washington, DC: Lawrence D. Miles Value Foundation., 1989.

3. Snodgrass, Thomas J., and Muthiah Kasi. Function Analysis: The Stepping Stones to Good Value. Madison, WI: University of Wisconsin, 1986.