P02 Economical Design

Question 1

Explain the Venecian ship building example!

Answer 1

A quantum leap in manufacturing technology of ships Venice developed methods of mass-producing warships in the Arsenal, including the „frame-first system“to replace the Roman „hull-first practice“ which for hundreds of centurieswas used.

The Venetian Arsenal operated similar to a modern production line. Ships moved down a canal and were fitted by the various shops they passed.

Question 2

What lessons can be learned from the Venetian example?

Answer 2

1. Sometimes to move away from established technology may be necessary to get a big/needed step ahead!
2. The total number of individual parts should be minimized.
3. Standardized parts and standardized components should be used (with proven design) where possible.
4. Modular components and subassemblies with standardized interfacesto other components should be used where possible.

Question 3

According to Henry Ford the principles of assembly lines are these:

Answer 3

1. Place the tools and the men in the sequence of the operation so that each component part shall travel the least possible distance while in the process of finishing.
2. Use work slides or some other form of carrier so that when a workman completes his operation, he drops the part always in the same place—which place must always be the most convenient place to his hand—and if possible have gravity carry the part to the next workman for his own.
3. Use sliding assembling lines by which the parts to be assembled are delivered at convenient distances.

Question 4

What is DFM?

Answer 4

“Design for manufacturing (DFM)”is the general engineering art of designing products in such a way that they are easyto manufacture in order to save resources!

Question 5

Explain the operational aspects and strategic aspects of “Design for manufacturing (DFM)”.

Answer 5

• Strategic DFM aspects are aspects of the competitiveness of the company and are discussed on the enterprise level!
• Operational DFM aspects are aspects of the success of a project or a contract and are discussed on the workshop / design office level!

Question 6

Name the obvious benefits of DFM!

Answer 6

cost, quality and delivery (QCD)

Question 7

What is the aim of DFA?

Answer 7

The aim of design for assembly (DFA) is to simplify the product so that the cost of assembly is reduced. However, consequences of applying DFA usually include improved quality and reliability, and a reduction in production equipment and part inventory.

Question 8

Design for Assembly (Example)

Answer 8

• Rail vehicles (rolling stock), cars as well as many other products are produced in assembly line production.
• The assembly is split between several work stations. At each of these workstations very specific work operations occur and all working simultaneously. That material required for these operations, is transported to the respective work stations. The special tools needed are available here.
• The product is transported from one work station to the next.
• The station at which the working process requires the longest time, determines the work cycle (clock rate).

Question 9

Explain Benchmarking!

Answer 9

Benchmarkingis the process of comparing one’s business processes and performance metrics to industry bests or best practices from other companies.

Dimensions typically measured are quality, time and cost.

Question 10

Explain Poka-Yoke!

Answer 10

“PokaYoke” is a Japanese phrase meaning “mistake avoidance“ and helps people and processes to work right the first time.

Question 11

Explain Kitting!

Answer 11

Kitting is the process of placing two or more items together to form one group of product.
Putting components into kits saves money because the seller would give a discount off each part and saves time when to assemble the product.

Question 12

What is DFT?

Answer 12

Design for Testability is a design techniques that add certain testability features to a hardware product design.
The premise of the added features is that they make it easier to develop and apply manufacturing tests for the designed systems or subsystems.

Question 13

Explain tolerancing!

Answer 13

Geometric dimensioning and tolerancing (GD&T) is a system for defining and communicating engineering tolerances. It uses a symbolic language on engineering drawings and computer-generated three-dimensional solid models that explicitly describe nominal geometry and its allowable variation. It tells the manufacturing staff and machines what degree of accuracy and precision is needed on each controlled feature of the part

Question 14

Name the two different approaches to the calculation of tolerance!

Answer 14

• Arithmetical (best case –worst case) tolerance calculations
• Statistical tolerance calculations