6.1 Establishing Functions

Question 1

What two things do a bookcase do according to an engineer?

Answer 1

A bookcase does at least two things:

1. It resists the force of gravity exactly to support the weight of the books
2. it enables the organization of those books with dividers or by its shelf lengths.

Thus, a bookcase doesn’t “just sit there.”

Question 2

What is essential to understand for successful design?

Answer 2

Understanding functionality is essential to successful design. Consequences are often tragic for failing to understand and design for all of a design’s functions.

Question 3

Define and explain functions.

Answer 3

Functions:

• those things a designed device or system is supposed to (must) do.
• typically expressed as action verb-noun couples
• Input Is Transformed into Output
  
  • This is reminiscent of elementary calculus in y = f(x)
    
    • function f(x) transforms the input of the independent
    • variable x into an output of a dependent variable y.

Question 4

What do engineering functions involve?

Answer 4

Engineering functions involve the transformation or transfer or flow of energy, materials, or information. Input is transformed into output.

Question 5

What are some examples of functions expressed in verb-noun pairs?

Answer 5

Statement of a function typically couples an action verb to a noun or object:

• lift a book
• support a shelf
• transmit a current
• measure a temperature
• switch on a light

Question 6

What might the object in a verb-noun formulation function start off with?

Answer 6

The object in a verb-noun formulation function may start off with a specific reference to a particular design idea.

Question 7

What is usually better to do instead of starting off the object in a verb-noun formulation function with a specific reference to a particular design idea.

Answer 7

It is better to be more general in the beginning. Start of looking for more generality in expressing functions.

Question 8

Use an example to explain why generality is preferred for verb-noun formulation functions in the beginning.

Answer 8

Example:

• Overly specific verb-noun pairing function:
  
  • Bookcase function is “support books.”
• Problem with this statement:
  
  • Bookcase shelves often support trophies, art, or even piles of homework.
• A more useful statement of the function to be performed:
  
  • To “resist forces due to gravity,“ and can be associated with the object’s weight (capacity).