CONCEPTUAL DESIGN TECHNIQUES


1) Needs and Goals
  – Need statement
  – Objectives tree
  – Functional analysis

2) Concept Development
  – Brainstorming
  – Morphological chart 

3) Concept Evaluation
  – Sketch concepts

  – Evaluation Matrices


     A morphological chart is a table based on the function analysis. On the left side of the chart the functions are listed, while on the right side, different mechanisms which can be used to perform the functions listed are drawn. It is a visual aid used to come up with different ideas. The idea generation is accomplished by creating single systems from different mechanisms illustrated in the morphological chart.  It is advised to generate several feasible designs using different mechanisms for each function for each concept.

BENEFITS

• Allows visualization of design space
– Gives us a sense of size
– Allows us to identify potential designs
– Allows us to identify and exclude incompatible 
   alternatives

HOW TO CREATE?

• Make list of features we want the design to have 
or functions we want it to perform
– Should be manageable size
– All features/functions at similar level of detail
• Build a list of means of achieving each function 
and create a table
• Choose one means from each row to combine 
into a design
• Number of possible designs = (#entries row 1) x 
(#entries row 2) x (#entries row 3) x ...
– Not all are feasible

     Figure 1 depicts a morphological chart for a vegetable collection system, continued from the Lateral Thinking Model above. See how the Generated Alternatives from before have now been formed into a matrix with images to help explain further. These sketches don’t have to be Monet, but they do need to clearly describe the product. You would then pick a path through them to begin design Concept number 1, as Figure 2 suggests.


Figure 1: Morphological chart for a vegetable collection system


Figure 2 - Morphological Analysis for vegetable collection system with selections (Haik and Shahin 2011: 175)

You are NOW at a stage to begin concept design.

Your first few concept designs should follow different routes through the Morphological Matrix, that is why you have compiled it. Do not ignore it. In this instance;

Concept 1 could be – scoop > conveyor belt > water from well > bowl > track system > wind blown
Concept 2 could be – triangular plow > rotating mover > water from well > wheel > hand push
Concept 3 could be - scoop > conveyor belt > square mesh > wheel > hand push

     Once you begin to combine these ideas, you’ll gain momentum and start to generate lots of ideas, organise your thoughts, change, erase, scrap, retrieve from bin, enthuse, destroy and generally go through the generation process. The image below is a very good example of how you might sketch a number of alternatives to investigate different concepts.

ALWAYS ANNOTATE YOUR SKETCHES. It makes it easier for you to describe the process.

     It’s generally accepted that you should produce at least three well-considered concepts, annotated and developed to a level that is distinguishable as an acceptable solution. The diagram in Figure 3 represents how your ideas may begin to narrow as you develop your ideas.


Figure 3: Flexible design model (Pugh 1991: 75)

NEXT STEP

     The concepts arrived upon using the morphological chart are then screened against each other and against the customer needs. Always keep in mind the PDS and QFD you formed and constantly check back to ensure you’re keeping with the guidelines. You will decide upon a Final Concept using Pugh’s Matrix at the next step.   This is done as a preliminary decision matrix (Evaluation matrices) to see which concepts are going to be further analyzed.


“An idea is nothing more nor less than a new combination of old elements.” (Foster 2007: 13).