Functional Descriptions
Teco-61
M. Reber
01_04
What is a functional
description??
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An overall description of the function and
appearance of the entire mechanism
A description of the function and appearance of each
major part of the mechanism
An explanation of how the mechanism operates or
is used and how each part contributes to the
functioning of the whole
Functional Descriptions focus on physical,
quantifiable details
They are often also called a mechanism description
or a product specification
What are functional
descriptions used for??
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To instruct the assembler/repairperson
To market a product to prospective
buyers
To explain a product to an owner
How are functional
descriptions organized??
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By location (spatially)
According to function
For example, if you are trying to describe a car for new
owners, you might organize according to location so that
your reader will learn about the comforts and
conveniences available to them when sitting in the
passenger compartment. If you are describing a car for
mechanics who will have to diagnose and correct
problems, you would organize according to function.
What are the parts of a
functional description??
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Title
Introduction
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Names the object
Explains origin of the name
Explains its function or behavior
Describes its overall appearance
Lists its individual parts
Sections for the various parts
Drawings and other graphics
Conclusion
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Explains how it works or is used
Extended object/product
descriptions may also include:
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A scope statement: Indicates what you will and
will not specify and who will have which roles and
responsibilities
A definitions section: Establishes the meaning of
any specialized terms (both the scope statement and
definitions section can be incorporated into the
Introduction if they are short enough
A materials section: Specified required materials to
be used
An operating characteristics section: Lists
operational requirements (such as how much load
the product can bear) for design and construction
purposes
How do I write a functional
description??
1. Choose a product requiring description
2. Define the purpose, audience, and situation
3. Research the mechanism or product
4. Identify the parts and subparts
5. Plan the overall description
6. Sketch the headings you’ll use
7. Select the sources of description
8. Plan an introduction
9. Consider the format
10. Review and revise your draft
What are the “sources of
description”??
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Purpose: How is the item used? What are
the applications?
Size: How big or small is it? Can you
compare its size to something familiar?
Shape: How is it shaped? Can you compare
its shape to something familiar?
Color: What are its colors?
Texture, finish: How does it feel to the
touch? How does it look (shiny, dark, etc.)?
Dimensions: What are its length, height,
width, depth?
…sources of description (con’t.)
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Weight: How much does it weigh?
Materials of construction: What materials
were used to create it—wood, steel, cardboard?
Ingredients: If it is something that is mixed,
what are the ingredients?
Methods of attachment: How are the
different parts attached—glued, welded, bolted,
screwed, nailed?
Location, orientation of parts: What’s the
orientation of the parts to each other—above,
below, to the left or right, within?
…sources of description (con’t.)
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Age: How old is it?
Temperature: Is temperature an important
descriptive detail?
Moisture content: What’s the percentage of
water content?
Amounts: How many are there?
Capacity: How much can it hold?
Volume: What are the various measurements
of volume related to it?
…sources of description (con’t.)
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Smell, odor: What does it smell like?
Pattern, design: Does it have a certain
pattern or design associated with it?
Tips for writing functional
descriptions
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Be accurate!! (a small discrepancy in
measurement might mean an object
won’t fit where your reader needs it)
Be specific and concrete (give parts a
name, etc.)
Use simple language and analogies to
help readers visualize
Questions to ask myself
1. What is my purpose?
2. Who is my primary reader and what are
his/her needs?
3. Do I need a generalized description as an
overview or a specific description?
4. Where can I find the information needed
for this description? If I use sales
literature, have I deleted an biased
language?
5. Should my description be formal or
informal?
Questions to ask myself (con’t.)
6. What should my overview contain?
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a definition
a purpose statement
general appearance
illustration
a list of components
Questions to ask myself (con’t.)
7. How is the breakdown and description
of parts organized? Is this a logical
organization? Have I thoroughly
described each part and broken it into
components if necessary?
8. Do I need a conclusion? Should I add
a process description?
Your assignment
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Choose an object or simple machine you are
already familiar with and have at your
disposal and write a description of three to
five pages (model specific if possible)
At a minimum, you should have three
sections:
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An overview or introduction
A breakdown into parts with descriptions
Conclusion (explains how the object works)
Specify the purpose and the reader
Your assignment (con’t.)
Choose one of the following objects or an
appropriate one of your own choice:
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Blender
Air popcorn popper
Microwave
Blow dryer
Electric razor
Clock radio