1. Engineering Design GE121 Finding Answers to the Problem Part III / IV
Lecture 12A

2. Limiting Design Space to a Usable Size
Pragmatic (practical) issues related to how an artifact will be used, and how it will be made
Provides ‘guideposts’ for development of the search space – may narrow rather than expand the search space
Design alternatives must be functions of
User Needs
Available Technologies
External Constraints
(and some common sense!)

3. Limiting Design Space to a Usable Size (Continued)
Example – Design of vehicles for a campus transportation system
Candidate Vehicles
Simple bikes
High Tech bikes
Recumbent bikes
Tricycles
Rickshaws
User Needs may dictate consideration of:
Parking availability
Carrying Packages
Access for Handicapped

4. Limiting Design Space to a Usable Size (Continued)
Available Technologies may affect design alternatives:
Materials (affects appearance, manufacturing, price)
External Constraints may limit design alternatives:
Team’s area of expertise (may be expert in tricycle design)
Available Manufacturing Facilities (may dictate material)
Practical Considerations – Common Sense!
Invoke and apply constraints (similar to user needs, as above)
Freeze the number of attributes (avoid those unlikely to seriously affect design – i.e. color)
Impose some order on the list (which functions / features are most important)
Get Real! (watch out when silly / infeasible options are repeated too often)

5. Morphological Charts: Organizing Functions and Means to Generate Designs that Work
Morphological Charts - Important Alternative Development tools
Chart or Matrix
Functions or Key Features are listed in the first column
Alternate Means of achieving each function are given in that function’s row
Generating the Means for each function can be a highly creative process
Means do not have to be Words – some designers use sketches or thumbnails to show some alternative means

6. Morphological Charts (continued)
The Morphological Chart can be used to generate Complete Alternatives
Leftmost column lists ALL functions
Selecting a means from EACH row guarantees that the solution satisfies all required functionality
Will NOT, however, guarantee that
Alternatives will WORK
Or even be internally consistent (see Fig. 5.2b)
Judgement is still required
This approach can result in a HUGE number of alternatives
The morph chart in Fig 5.2 can be used as an example of internal consistency and judgement. If “glass” is the selected material, then “box” and “bag” aren’t consistent containers. If “bottle” is the container, then “waxed cardboard” and “lined cardboard” are not good choices for material.

7. Morphological Charts (continued)
Start with Functions
Contain Beverage
Material for Beverage Container
Provide Access to Juice
Display Product Information
Sequence Manufacture of Juice and Container

8. Morphological Charts (continued)
Add Means for Each Function
Contain Beverage: Can, Bottle, Bag, Box
Material for Beverage Container: Aluminum, Plastic, Glass, Waxed Cardboard, Lined Cardboard, Mylar Films
Provide Access to Juice: Pull-Tab, Inserted Straw, Twist-Top, Tear Corner, Unfold Container, Zipper
Display Product Information: Shape of Container, Labels, Color of Material
Sequence of Manufacture: Concurrent , Serial

9. Morphological Charts (continued)
Create Morph Chart (words)
Work through this example on inconsistencies such as “glass-bag” or judgements such as “bottle-waxed cardboard”.
There are obvious combinations that can be eliminated: such as “can-tear corner” and “bottle-unfold container”. However, thinking about unlikely combinations may spark creative ideas.
An implicit assumption in this chart is that the whole container must be made out of the same material (except for the mechanism for opening). Frozen juice concentrates have lined cardboard sides and metal lids. Is that (or another combination) feasible here?
Fig. 5.1 p104
Or – Use Thumbnails (next page)

10. Fig. 5.3 p106

11. Morph Chart Generating a Complete Alternative
Morph Chart showing one means for each function which can be combined to form one complete alternative that looks feasible
Fig. 5a

12. Morph Chart Complete Does not Mean Feasible
Morph Chart showing a complete alternative that is not consistent – Glass Bottle with a zipper (zip-lok requires plastic)
Fig. 5b

13. Managing Your Group
You may want to consider appointing someone to fill each of the following roles:
Project leader
Scribe/recorder
Project file keeper
Report co-ordinator

14. C-Sketch Method
It may be helpful to use the C-Sketch Method to generate ideas from your Morph Chart (examples from microlaryngeal stabilization device)

15. Activity Create a Morph Chart for your project
Start with a List of functions
Brainstorm a List of Means for each Function
Be Creative in your Brainstorming!