Function Definition
A Powerful Problem or Opportunity
Analysis Technique
© G. A. Motter, 2006 & 2008
Define the Project
Define
Identify
CCRs
Business Case, Opportunity Statement, Goal,
Scope and Boundaries
Capture & Analyze Voice of the Customer
Identify Critical Customer Requirements (CCRs)&
Establish System Level Engineering Specifications
Identify System Design Concept
Determine System Functionality
Flow Down of CCRs to Sub-Assemblies and parts
Design
Relate CCRs (Ys) to Design Parameters (x’s)
Typical
Design for Robust Performance
DFSS
Develop Detailed Design
Minimize Sensitivity to Design & Operating Variations
Design for Manufacturability
Optimize
for 6
Process
Minimize Sensitivity to Mfg Variations
Predict Quality
Predict  Iterate to Meet Quality Target
OK
Test & Validate
Validate
Assess Performance, Reliability, Mfg, ...
OK
Deliver to Customer
© G. A. Motter, 2006 & 2008
Source: Design for Six Sigma, K. Yang
Objectives
• Learn “Best Practices” to Define Functions
• Identify Basic and Secondary Functions
• Develop a FAST Diagram
• Intro. to Value Engineering
• Assign Homework
FAST: Function Analysis System Technique
© G. A. Motter, 2006 & 2008
Function Definition
• A description of a product expressed as an Active
Verb and a Measurable Noun
• Provides a complete understanding of the basic
reason(s) something exist
• Explore new ways to deliver Customer Satisfaction
– Improved performance
– Lower cost
© G. A. Motter, 2006 & 2008
Steps to Function Definition
1. Define Project Scope
2. Define the Functions
3. Construct the FAST diagram
4. Perform FAST diagram logic checks
FAST = Function Analysis System technique
© G. A. Motter, 2006 & 2008
Source: Value Management, J. Kaufman
1.) Project Scope is a Lead Pencil
PENCIL
COMPONENTS
ERASER
BAND
BODY
PAINT
LEAD
© G. A. Motter, 2006 & 2008
This product could
be anything:
• Power Supply
•
•
•
•
•
Circuit Breaker
Data Base
Software
Radar Set
etc.
Source: Value Management, J. Kaufman
2.) Define the Functions for your Project
Functions are defined in two word phrases
• Active Verb:
– Describes the specific action we plan to carry out to achieve our intended
purpose
• Measurable Noun
– Defines the object on which the action operates
• Any Verb may be combined with any Noun to describe a
desired Function
Acid Test – “Does it describe what something
actually does in the system under study?”
© G. A. Motter, 2006 & 2008
Verbose Descriptions Indicate Lack of
Design Understanding
Start Engine
Establish Budget
Steer Automobile
Increase Incentive
Stop Automobile
Maintain Clearance
Remove CD
Prevent Contamination
Attract Attention
Protect Children
Reduce Size
Tighten Bolt
Collect Data
Reward Achievement
Collect Dirt
Save Time
Control Deflection
Transmit Information
Create Image
Cut Grass
Educate Students
Suppress Noise
© G. A. Motter, 2006 & 2008
Verbs to Avoid
Passive and Indirect Verbs
Provide
Give
Is
Supply
Furnish
Prepare
Review
Attend
Goal-Like Verbs
Improve
“ize” words
Optimize
Least
Maximize
Prioritize
Present
Minimize
Economize
© G. A. Motter, 2006 & 2008
Tips for Active Expressions
• Important to use active Verbs rather than passive Verbs
• To change passive description to active, try using the noun
as the verb and select another noun
Examples
Passive
Active
Provide Support
Support Weight
Seek Approval
Approve Procedures
Develop Exhibits
Exhibit Products
Submit Budget
Budget Expenses
Determine Resolution
Resolve Problem
Functions are intended to be taken literally as we attempt to bring
clarity in describing WHAT a system actually does
© G. A. Motter, 2006 & 2008
Source: Stimulating Innovation in Products and Service with Function Analysis and Mapping
Function Description Of A Lead Pencil
Pencil
Components
© G. A. Motter, 2006 & 2008
Description
ERASER
Remove Marks
BAND
Secure Eraser
Improve Appearance
BODY
Support Lead
Transmit Force
Accommodate Grip
PAINT
Protect Wood
Improve Appearance
Display Information
Deliver Message
LEAD
Make Marks
Source: Value Management, J. Kaufman
3.) Every Design has Basic and
Secondary Functions
Basic Function:
• Principal reason for the product’s existence
• Has value to the Customer
• Loss of Basic Function results in total loss of market value for
the design
• May be Performance or Esteem based
Secondary Function:
• Assist in, or necessary for, the realization of a Basic Function
• Targets for modification and/or elimination to:
– Reduce cost
– Reduce design complexity
– Achieve Breakthrough in design
© G. A. Motter, 2006 & 2008
Source: Value Management, J. Kaufman
Basic and Secondary Functions Of A Pencil
Pencil
Components
Description
Functions
(Basic or Secondary)
ERASER
Remove Marks
Secondary
BAND
Secure Eraser
Improve Appearance
Secondary
Secondary
BODY
Support Lead
Transmit Force
Accommodate Grip
Secondary
Secondary
Secondary
PAINT
Protect Wood
Improve Appearance
Display Information
Deliver Message
Secondary
Secondary
Secondary
Secondary
LEAD
Make Marks
Basic
Why someone
buys a pencil
© G. A. Motter, 2006 & 2008
Source: Value Management, J. Kaufman
3) Construct the FAST Diagram
FAST Diagram
– Visual layout (Tree Diagram) of the
product’s Functions
– Starts with the Basic Function, and builds
to the right with supporting or Secondary
Functions
Why do a FAST Diagram?
– Help understand which
Functions provide the best
opportunities to be
eliminated, or improved, to
deliver the Basic
Function(s)
© G. A. Motter, 2006 & 2008
Construct FAST Diagram Left to Right,
and Check it Right to Left
Ask How ?
Secondary Function
Secondary Function
Basic Function
Secondary Function
Secondary Function
OR logic
AND logic
Secondary Function
1.
2.
3.
Ask Why ?
Identify what you feel is the Basic Function.
Place Secondary Functions to the right of the Basic Function. Ask the
question: “How is this Function actually accomplished?”
Check the FAST diagram by starting at the right and working left. Ask the
question: “Why must this Function be performed?”
© G. A. Motter, 2006 & 2008
Source: Value Management, J. Kaufman
Example: Lead Pencil FAST Diagram
Ask How ?
Display
Information
Improve
Appearance
Record
Information
Keep
Records
Make
Marks
Deposit
Medium
Maintain
Information
Apply
Pressure
Secure
Eraser
Correct
Information
Remove
Marks
Absorb
Medium
Support
Lead
Protect
Wood
Transmit
Force
Accommodate
Grip
Apply
Pressure
Ask Why ?
Rub
Eraser
© G. A. Motter, 2006 & 2008
Example Mouse Trap
Ask Why ?
Objective: Eliminate Mice
Attract
Mouse
Bait
Trap
Set
Trigger
Kill
Mouse
Strike
Mouse
Release
Striker
Trip
Trigger
Arm
Trap
Position
Striker
Ask How ?
Release
Energy
© G. A. Motter, 2006 & 2008
Store
Energy
Compress
Spring
Example:
Sliced Ham Process
Ensure
Flavor
Add Flavoring
Inject Brine
Spread Flavoring
Adjust Meat Color
Remove Air Bubbles
Produce
Sliced
Ham
Enhance
Appearance
Retain Brine
Add
Coloring
(to Meat)
Tenderize
Meat
Form Meat
Remove Fat
Remove Casing
Lower Meat
Temp
Space Meat Length
Fabricate
Slices
© G. A. Motter, 2006 & 2008
Determine Meat
Weight
Fix Meat
Thickness
Source: Function Analysis, K. Akiyama, pg 207
Four Rules of Function
Definition
1. Once defined, the Basic Function cannot change; it
becomes the principle work the system does.
Example: A flashlight is expected to emit light
2. The cost contribution of a Basic Function is usually
minimal percentage of total cost
3. Can not sell supporting Secondary Functions without
performing the Basic Function satisfactorily
4. Loss of Basic Function(s) causes loss of market
value. Example a Rolex watch that does not display
correct time
© G. A. Motter, 2006 & 2008
4.) FAST Diagram Logic
Checks
 Double check tree diagram “How?” and “Why?” logic.
 Identify possible Secondary Functions for elimination?
 Test by removing Secondary Function, and ask the
“How ?” and “Why ?” logic questions.
 Check “AND” logic and “OR” logic diagramming.
 Ensure project Scope lines are clearly drawn.
© G. A. Motter, 2006 & 2008
Cost Function Matrix is Workhorse of
Value Engineering
Operations, Parts,
Assembly
Total
Cost
Functions (V-N)
Total
%
Operations, Parts, and
assemblies come from:
- Block diagram
- Process Map
- Logic Diagram
- Value chain
© G. A. Motter, 2006 & 2008
Functions come from
detailed level of FAST
Diagram
Cost – Function Matrix Identifies
Areas of Opportunity
Steps to Create Matrix:
1.) List major operations, parts, or assemblies in left
hand column
2.) List total cost for each group in adjacent column
3.) Place Functions across top from FAST Diagram
4.) Identify Functions contributing to each line of cost
(indicate with dot in cell)
5.) Determine portion of cost associated with each
function
6.) Sum Functional cost
7.) Calculate Function %
8.) Show Function % on FAST diagram
© G. A. Motter, 2006 & 2008
Example: International North Atlantic Ice Patrol
• Formed in 1913
• Result of Titanic sinking
April 14, 1912
• Iceberg condition data collected by
• Fixed wing aircraft
• Buoys
• Report warnings at 9 pm
each day in “plain, concise
English” during ice season
from February thru July.
© G. A. Motter, 2006 & 2008
Purchase
Sensors
Hire
Operators
Ask How ?
Locate
Icebergs
Example:
International Ice
Patrol
Move
Operators
Move
Sensors
Compile
Messages
Receive Ship
Data
Send Iceberg
Warnings
Predict
Iceberg
Position
Collect Data
Predict Ice
Drift
Transmit
Radio
Messages
Establish
Station
Operate
Radio
Ask Why ?
© G. A. Motter, 2006 & 2008
Source: Value - Its Measurement, Design, and Management by M.L. Shillito Fig 7.7
Total
%
© G. A. Motter, 2006 & 2008
56
56
1
63
13
Operate
Transmitter
56
Establish
Stations
235
247
245
76
Predict Drift
Move Sensors
235
247
245
76
Collect Data
Move Operators
235
Receive Ship
Data
Hire Operators
Total
Cost $M
Aircraft Personel
705
Fuel
494
Aircraft Maintenance
490
Aircraft Op. Support
152
Office Staff
224
Travel/Lodging
50
Leasing
5
Bouys
63
Radar Film
13
Misc.
5
Admin.
480
Purchase Sensors
Example: International Ice Patrol
Cost-Function Matrix
56
4
5
120
120
120
120
$2,681
77
235
853
803
176
176
176
9
176
100
2.9
8.8
32
30
6.5
6.5
6.5
0.3
6.5
Note: Cost in 1983 dollars
Source: Value – Its Measurement, Design, and Management by M.L. Shillito, Fig 7.8
Example: International Ice Patrol
Ask How ?
Locate
Icebergs
$2,056,000
Compile
Messages
$2,496,000
Send Iceberg
Warnings
Predict
Iceberg
Position
$2,681,000
(1983)
$440,000
Transmit
Radio
Messages
$185,000
© G. A. Motter, 2006 & 2008
Purchase
Sensors
2.9%
Hire
Operators
8.8%
Move
Operators
32%
Move
Sensors
30.0%
Receive Ship
Data
6.5%
Collect Data
6.5%
Predict Ice
Drift
6.5%
Establish
Station
0.3%
Operate
Radio
6.5%
Target for cost
reduction
Ask Why ?
Source: Value - Its Measurement, Design, and Management by M.L. Shillito Fig 7.7
Homework Assignment
Objective
• Develop a FAST Diagram for your ECE 480 Senior Design Project
Instructions
• Provide a few sentences describing your Senior Design Project
design objectives to orient me in grading this homework assignment
• Follow Step-By-Step process in slides
• Refer to examples in Slides and Appendix
• Refer to Appendix for list of useful Verbs and Nouns
• Only diagram a maximum of 3 levels of Secondary Functions beyond
Basic Function
Deliverables
• Typed FAST Diagram in Microsoft Word, Excel, or PowerPoint for
each Team
• E-Mail Diagram to G. Motter at sail1070@Yahoo.com and to Dr.
Goodman
Due Date
• October 6, 2008
© G. A. Motter, 2006 & 2008
Questions?
© G. A. Motter, 2006 & 2008
Appendix
Classical Text Book Examples
© G. A. Motter, 2006 & 2008
Useful Verbs in Describing Functions
Add
Display
Maintain
Sense
Analyze
Distribute
Measure
Separate
Arrange
Eliminate
Obtain
Start
Attach
Evaluate
Position
Store
Create
Expand
Prevent
Support
Collect
Extend
Protect
Test
Combine
Freeze
Recommend
Transmit
Confirm
Harden
Record
Transport
Contain
Heat
Reduce
Use
Conduct
Implement
Remove
Verify
Control
Increase
Resist
Convert
Insulate
Retain
Cool
Invert
Reverse
Destroy
Isolate
Rotate
Develop
Locate
Select
© G. A. Motter, 2006 & 2008
Source: Stimulating Innovation in Products and Service with Function Analysis and Mapping
Useful Nouns in Describing Functions
Air
Fluid
Noise
Time
Area
Force
Opening
Torque
Assembly
Frequency
Pressure
Vehicle
Atmosphere
Friction
Protection
Vibration
Cold
Gas
Resistance
Volume
Color
Heat
Resistance
Voltage
Comfort
Humidity
Rotation
Waste
Communication
Indication
Shape
Water
Component
Information
Size
Wear
Current
Length
Solid
Weight
Distance
Material
Sound
Enclosure
Mixture
Space
Energy
Mobility
Stress
Environment
Moisture
Temperature
Expansion
Motion
Texture
© G. A. Motter, 2006 & 2008
Source: Stimulating Innovation in Products and Service with Function Analysis and Mapping
Example:
Paper Punch
Locate
Sheet
Support Sheet
Ask Why ?
Drive Punch
Pierce Sheet
Guide Punch
Retract Punch
Organize
Paper
Produce
Holes
Adjust
Holes
Locate Punch Assembly
Drop Holes
Task
Basic
Function
Collect Waste
Collect Holes
Prohibit Rust
Attract User
Scope
Ask How ?
© G. A. Motter, 2006 & 2008
Protect Work Surface
Decorate Surface
Source: Acquiring, Processing, and Deploying the Voice of the Customer, M. Shillito, pg 74
FAST Model is complete when Customer Needs can be
Mapped to Secondary Functions
Ask How ?
Customer
Task
Basic
Function
Secondary
Function
SF
1. Need
2. Need
SF
Secondary
Function
1. Need
SF
1. Need
2. Need
3. Need
SF
Secondary
Function
SF
1. Need
2. Need
SF
1. Need
© G. A. Motter, 2006 & 2008
Ask Why ?
Mapping of Voice Of Customer to Functions
Example: Paper Punch
Locate Sheet
•
•
Easy to insert
Stays in place
Pierce Sheet
Produce
Holes
•
•
•
•
Easy to press
Won’t hurt hand
Pierce multiple sheets
Non-jamming
Adjust Hole (location)
•
•
•
•
Easy access to assembly
Easy to position
Finger tight
Stays in place
Collect Waste
•
•
•
© G. A. Motter, 2006 & 2008
Holds large quantity of holes
Holes won’t fall out
Easy to clean
Example:
Function Tree - Flashlight
Ask How ?
Convert Electricity
to Light
Send Current
Generate Light
Protect Bulb
House Parts
Hold Bulb
Collect Light
Ask Why ?
Open/close
circuit
Form Circuit
Store Electrical
Energy
Reflect Light
Illuminate
Surroundings
Basic
Function
Fit Grip
Hold Body
Retain
Appearance
© G. A. Motter, 2006 & 2008
Adsorb Force
Source: Function Analysis, K. Akiyama, pg 55
Verbose Descriptions Indicate Lack of
Design Understanding
Object
Function Definition
Verb
Noun
LED Array
Illuminate Surroundings
Fuse
Limit Current
Flash Memory
Store Information
Rectifier
Convert Current
Spreadsheet
Organize Data
© G. A. Motter, 2006 & 2008
Appendix
Past ECE 480 Project Examples
© G. A. Motter, 2006 & 2008
Decode
Information
Refrigerator Ice
Level Detection
Have
Information
Display
LED
Have Power
Source
Emit Light
Task
Basic
Function
Detect Ice
Level
Output
Height
Transfer
Image
Capture
Picture
Decode
Image
Have Power
Source
Have
Algorithm
Time Image
Capture
Sense
Environment
Have
algorithm
Have Ice
Bin
Close
Freezer Door
Prepare
Camera
Stop Ice
Maker
© G. A. Motter, 2006 & 2008
Display
Object
Height
(inches)
Measure
Height
Activate
Sensing
System
Implement
and Run
Code
Detect
Object
Send Signal
Locate Brim
Of Object
Calculate
Voltage
Change
Convert Analog
Signal to Digital
Signal
Collect Data
Determine
Distance
© G. A. Motter, 2006 & 2008
Use
Algorithm
Team 13 Digital Answering Machine
FAST Diagram
Detect Rings
Receive Messages
Basic Function
Connect Line
Answer Phone
Detect Dial-tone
Disconnect Line
Store Messages
Record Audio
Digitize Signal
Secondary Functions
Store Date/time
Playback Messages
© G. A. Motter, 2006 & 2008
Volume Control
Amplify Audio
Convert Message
Retrieve Message
Display Date/time
Retrieve Date/time
ECE480
Active EMI Filter
Sense
Noise
Couple to Filter
Input
Amplify
Noise
Measure
System Error
Reduce
Low Frequency
Noise
Correct For Noise
Error
Compensate
Amplifier
For Error
Cancel Currents
Design EMI Filter for
Automotive
Application
Reduce
Conducted
Noise
Pass DC through
Filter
Combine with
Existing Noise
Cancel Voltages
Increase Series
Impedance at High
Frequencies
Use
Inductors
Short High
Frequency Noise
To Ground
Use
Capacitors
Reduce
High Frequency
Noise
© G. A. Motter, 2006 & 2008