1. Using the Decision Matrix
A Brainstorming Method Used to Help Students Uncover Solutions to Engineering Problems
Engineering Design & Development
Created By: Dale A. Coalson

2. Step 1…create a precise problem statement
Best way to cut residential grass standing over 12”

3. Step 2…insert design criteria in top row
Inexpensive
Reliable
Safe
Practical
Aesthetics
Legal
Moral
Operating $
Best way to cut residential grass standing over 12”

4. Sample Constraint Terms
Feasible
Reliable
Economical
Aesthetic
Legal
Moral
Safe
Timely
Functional
Environment Friendly
Ergonomics
Practical
Ease of Manufacture
Standard Parts
Ethical
Efficient

5. Step 3…Brainstorm ANY and ALL Ideas
Inexpensive
Reliable
Safe
Practical
Aesthetics
Legal
Moral
Operating $
Best way to cut residential grass standing over 12”
Step 3…Brainstorm ANY and ALL Ideas
Rotary Riding Mower
Fire
String Line
Herbicide
Fence Salt
Fenced Herbivore
Gas Push Mower
Garden Hoe

6. Step 4…Rate your matrix using the “Reasonable Man” theory
Work Thru. Each Column
Inexpensive
Reliable
Safe
Practical
Aesthetics
Legal
Moral
Operating $
Best way to cut residential grass standing over 12”
Rotary Riding Mower
Fire
String Line
Herbicide
Fence Salt
Fenced Herbivore
Gas Push Mower
Garden Hoe - - +
ADD - + + - +
Step 4…Rate your matrix using the “Reasonable Man” theory

7. Other Scale Qualifiers
Having a beneficial impact = +
Having a detrimental impact = -
Having a neutral impact = 0
Using the popular scale of 0-10
{Whatever the ranking value make sure the alternative rows can be added up}

8. Reapply Matrix Cycle to Winner of First Attempt
Inexpensive
Reliable
Safe
Practical
Aesthetics
Legal
Moral
Operating $
Best Result From MATRIX #1
String Cutter???
Rework
String on Front of Mower
Use Under Riding Mower
String Cutter on Trailer
String Cutter on “Outriggers”
Steel Line
Chain Mounted Head
Robotic String Unit
Electric Assist String Cutter
Redefined Terms

9. Your Teams Turn