Functional Descriptions

1. Functional Descriptions Documenting Product Specifications

2. Definition of a Functional Description • 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 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

3. What Functional Descriptions are NOT • Not typical user instructions or documentation • Not comprised of steps or “how to“ instructions

4. Uses of Functional Descriptions • To instruct the assembler/repairperson • To market a product to prospective buyers • To explain a product to an owner

5. Functional Descriptions are Organized: • By location (spatially) • If you are describing 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 • According to function • If you are describing a car for mechanics, you might organize according to function so the reader can effectively diagnose and correct problems

6. Parts of a Functional Description • Title • Introduction • 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 • Explains how it works (NOT how to operate it!)

7. Extended Descriptions May Also Include: • 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

8. To Write a Functional Description: • Choose a product requiring description • Define the purpose, audience, and situation • Research the mechanism as appropriate • Identify the parts and subparts • Plan the overall description • Sketch the headings you’ll use • Select the sources of description • Plan an introduction • Consider the format • Review and revise your draft

9. Document All “Sources of Description” • 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?

10. “Sources of Description” (cont.) • 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?

11. “Sources of Description” (cont.) • 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?

12. “Sources of Description” (cont.) • Smell, odor: What does it smell like? • Pattern, design: Does it have a certain pattern or design associated with it?

13. Tips for Writing Functional Descriptions • 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

14. Questions to Ask Myself • What is my purpose? • Who is my primary reader and what are his/her needs? • How can I learn about the object and its function? (experimentation, literature) • What major headings do you plan to use? • What should my overview contain? • A definition, a purpose statement, general appearance, illustration, a list of components?

15. Questions to Ask Myself (cont.) • How is the breakdown and description of parts organized? Is the organization logical? • Have I thoroughly described each part and broken it into components if necessary? • What pictures and graphics effectively explain the object? (Cite your sources.) • Do I need a conclusion?

16. Your Assignment • Choose an object or simple machine you are already familiar with and have at your disposal. For example: • Blender • Air popcorn popper • Blow dryer • Electric razor • Write a description of three to five pages (model specific if possible) • At a minimum, you should have three parts: • An overview or introduction section • A breakdown into parts with descriptions • Conclusion (explains how the object works)

17. Tips for Completing Your Assignment • Understand the purpose and the audience • Be model-specific • Do not do any outside research!! (graphics excepted) • Learn about the object through experimentation • Be sure to provide citations for any graphics you did not create