1. Axiomatic Design Theory
What is axiom?
is known to be true by understanding its meaning without proof.
a starting point for deducing and inferring other (theory dependent) truths.
Axiomatic design theory: it is a design theory that has been verified by numerous applications. In other words, it is true (starting point) and accepted by engineers without proof.

2. Axiomatic Design Theory
Axiom 1: Independence Axiom
Axiom 2: Information Content

3. Axiomatic Design Theory (Axiom 1)

4. Axiom 1 – Design example Requirement:
hold hot (~100oC) water with hand
Hold hot water
Grasp the holder
One of the motives is to
As we know,
Hold water without consideration of temperature
Resist heat conduction

5. Resist heat conduction Grasp the holder
Isolating material
Hold water without consideration of temperature DP
One of the motives is to
As we know,

6. Axiom 1 The better design meets:
Design or function requirement (FR) should be independent or uncoupled on their own right
Design parameters (DP) should maintain the FR independent – i.e., not making FR coupled

8. Uncoupled
(Diagonal matrix)
To satisfy the independence axiom, the design matrix must be either diagonal or triangular
Coupled
(Full matrix)
Decoupled
(Triangular matrix)

9. Example – Axiom 1
Hinge
One of the motives is to
As we know,
FR1=Provide access to items stored in the refrigerator
FR2=Minimize energy loss

10. Hinge S1’=Horizontally hung door
FR1=Provide access to items stored in the refrigerator
FR2=Minimize energy loss
One of the motives is to
As we know,
S1=Vertically hung door
S2=Thermal insulation material in the door

11. Hinge Decoupled Uncoupled
The cold air stays inside when the door is opened

12. Contain axial pressure,
12 FRs:
Contain axial pressure,
Withstand a moderate impact when the can is dropped,
Provide easy access to liquid, etc.
Physical pieces: Just 3
(the body, the lid, the opener tab)
DPs: 12
The thickness of the can body
The curvature at the bottom of the can etc.
Axiom 1 is focusing upon Functional independence but not physical independence

13. Notion: logical and physical
Physical integration
FR and DP in ADT refer to the logical level
FR1/DP1
One
FR2/DP2
One of the motives is to
As we know,
Notion: logical and physical

14. Solution principle 1 for opening type 1 of lid
At the conceptual design phase
Solution principle 2 for opening type 2 of lid
At the conceptual design phase
One of the motives is to
As we know,
The geometry of each of them refers to the embodiment design phase
Their relationship (distance, material interface) refers to the embodiment design phase

15. Decoupled Design
One of the motives is to
As we know,

16. Decoupled Design Step 1: Change DP1 to affect FR1 and FR2
One of the motives is to
As we know,
Step 1 has also affected FR2 but in Step 2, this effect is changed back and to further affected by DP2 only

17. Axiom 1 revision The better design meets:
Design or function requirement (FR) should be independent or uncoupled on their own right
Design parameters (DP) should maintain the FR independent – i.e., not making FR coupled
Remark: In the recent development, decoupled situation of FR will also be considered in Axiom 1, i.e., acceptable as a better design.

18. Redundant design

19. Redundant design
One of the motives is to
As we know,

20. Summary
Axiom 1 of ADT concerns coupling, decoupling, and uncoupling among functional requirements both in direct and indirect (through DP) manners.
Axiom 1 suggests the better design to be uncoupled or decoupled.
Logical design versus physical design.
Physical design refers to embodiment design.
Axiom 1 of ADT is only applicable to the conceptual design.
One of the motives is to
As we know,

21. Summary Redundant design concept: more DP than FR.
It is a relative concept about coupling, decoupling and uncoupling.
One of the motives is to
As we know,