Axiomatic and robust design

Question 1

What is design?

Answer 1

DESIGN = An interaction process where we are “zig-zagging” between WHAT we want to achieve and HOW we will achieve this.
The goal (WHAT) is specified in the functional domain as functional requirements (FRs).
Solutions (HOW) fulfilling the goal are generated and defined in the physical domain as design parameters (DPs).

Question 2

Explain axiomatic design

Answer 2

Axiomatic Design supports the design decision making process
* Correct decisions
* Shorten lead time
* Improves the quality of the product
* Deal with complex systems
* Simplify service and maintenance
* Enhance creativity
It provides methods to analyze the “goodness” of a design solution.

Question 3

What is the independence axiom?

Answer 3

Axiomatic Design supports the design decision making process with a set of axioms. The first axiom is the independence axiom. And it means “Maintain the independence among functional requirements (FRs)”
Meaning that:
* Functional requirements (FRs) should be independent or uncoupled
* Design parameters (DPs) should maintain the FRs independent, i.e. not making FRs coupled
- Axiomatic design = Make funtional requirements (FRs) and design parameters
(DPs) as uncoupled as possible.

Question 4

What is robust design?

Answer 4

A product is robust when its functionality is insensitive to:
–>Material variation
–>Manufacturing variation
–>Operational variation
The main idea with robust design is to improve
product quality (reduce the output variation)
without eliminating the variation sources.
(Reducing variation sources may increase cost.)
- Robust design = make the product insensitive to variation

Question 5

What is locating schemes (P-frames)?

Answer 5

The purpose of a locating scheme is
to lock the position of a part in space.
The master location scheme is the set
of 6 locating points on a part that
locates the part in the:
* manufacturing fixture (as far as possible)
* inspection fixture
* assembly fixture
* final assembly/product

Question 6

What is the 3-2-1 locating scheme?

Answer 6

• Primary points A1, A2 and A3 defines a
  plane and locks the geometry in space in two
  rotations and one translation: TZ, RX, RY
• Secondary points, B1 and B2, defines a line
  and locks the geometry in space in one
  rotation and one translation: TY, RZ
• Tetriary point C1 locks the geometry in space
  in one translation: TX