Download - © 2008 Pearson Education South Asia Pte Ltd Chapter 16: Product Design and Manufacturing in a Global Competitive Environment Manufacturing Processes for.

© 2008 Pearson Education South Asia Pte Ltd© 2008 Pearson Education South Asia Pte Ltd

Chapter 16: Product Design and Manufacturing in a Global Competitive EnvironmentChapter 16: Product Design and Manufacturing in a Global Competitive EnvironmentManufacturing Processes for Engineering Materials Manufacturing Processes for Engineering Materials

Manufacturing Processes Manufacturing Processes for Engineering Materials for Engineering Materials

(5(5thth Edition in SI Units) Edition in SI Units)Chapter 16: Chapter 16:

Product Design and Manufacturing Product Design and Manufacturing in a Global Competitive Environmentin a Global Competitive Environment



Index

• Quality• Material• Manufacturing• Cost



Product Design and Robust Design

• Software helps designers develop products which reduced assembly and manufacture time.

Some product design considerations:1. Simplified product design2. Environmental considerations3. Alternative designs4. Unnecessary features are eliminated5. Modular design



Product design and quantity of materials

• High production rates and reduced labour made automation and computer integration possible.

• Reductions in materials require selection of materials with high strength-to-weight ratios.

Robustness and robust design -• Robustness is defined as a design that functions within

acceptable parameters.• Yet its difficult or impossible to control.



Quality as a manufacturing goal

• Product quality includes well-defined technical considerations and human opinion.

• High product quality includes:1. High reliability2. Performs, functions well and safely3. Good appearance4. Inexpensive5. Upgradeable6. Robustness



Quality as a manufacturing goal

• Concept of continuous improvement in quality means that there should be never-ending improvement.

• Concurrent engineering design is to select specific materials for components for a particular product.

• Concept of return on quality (ROQ) is:1. Making sure quality is an investment.2. Limit on how resources should be explanded.3. Having quality improvement.



Total quality management

• Total quality management (TQM) is a system that emphasizes that quality must be designed and built into a product.

• Both management and employees make an effort to manufacture high-quality products without any defects.

Quality circle• Concept consists of regular meetings.• Worker involvement, responsibility, creativity and team

effort are emphasized.



Deming methods



Taguchi methods

• High quality and low costs are achieved by engineering and statistical methods.

• Loss of quality will result in:1. customer dissatisfaction2. costs are incurred3. marketplace is diminished4. loses its company share in the market



Taguchi methods

• Taguchi methods of quality engineering emphasizes the importance of:

1. Enhancing cross-functional team interaction2. Implementing experimental design

Taguchi loss function

2

22

costt Replacemen where

cost Loss

TLSLk

TYk

σ = standard deviation of partsY = mean value from manufacturingLSL = lower specification limitationT = target value from designk = constant



High-quality polymer tubes are being produced for medical applications, where thetarget wall thickness is 2.6 mm, with an upper specification limit of 3.2 mm and a lower specification limit of 2.0 mm (2.6±0.6mm). If the units are defective, they are replaced at a shipping-included cost of $10.00. The current process produces parts with a mean of 2.6 mm and a standard deviation of 0.2 mm. The current volume is 10,000 pieces of tube per month. An improvement is being considered for the extruder heating system. This improvement will cut the variation in half, but it will cost $50,000. Determine the Taguchi loss function and the payback period for the original production process and incorporating the process improvement.

Example 16.1Production of polymer tubing



SolutionThe quantity k is given by

The loss cost is then

After improvement,

The savings are

The payback period for the investment is

Example 16.1Production of polymer tubing

28.27$

6.22.3

00.10$2

k

unitper $1.112.06.26.278.27cost Loss 22

unitper $0.281.06.26.278.27cost Loss 22

monthper 8300$000,1028.0$11.1$

months 02.6month/8300$/000,50$



The ISO and QS Standards

• Customers always demand high-quality products and services at low prices.

The ISO 9000 standard• Quality Management and Quality Assurance Standards

is a generic series of quality-system management standards.

• Companies which fail to meet the requirements of the standard will not be registered.



Life-Cycle Engineering and Sustainable Manufacturing

• Product life cycle is concerned with environmental factors, design, optimization and technical considerations of the product.

Cradle-to-grave• Consecutive and interlinked stages of a product or

service system.Sustainable manufacturing• The need for conserving these resources through

maintenance and reuse.



General properties of materials

• Mechanical properties of materials include strength, toughness, ductility, hardness and resistance to fatigue, creep and impact.

• Physical properties include density, melting point, specific heat, thermal and electrical conductivity, thermal expansion and magnetic properties.

• The chemical properties are oxidation and corrosion.



Shapes of commercially available materials

• Materials are available in various forms.



Manufacturing characteristics of materials

• Manufacturing characteristics include castability, workability, formability, machinability, grindability, weldability and hardenability through heat treatment.

• Quality of a raw material influences its manufacturing characteristics.



Substitution of Materials in Products

• Product improvements result from: 1. substitution of materials2. implement new designs, technologies or improved

processing techniques3. better control of processing parameters4. increased automation



Capabilities of Manufacturing Processes

• Casting and injection molding can produce complex shapes.

• Forgings have higher toughness.




Dimensional tolerances and surface finishing• Important for functioning of parts, machines, and

instruments and assembly operations.




Production quantity or volume• Manufacturing discipline is to determine the optimum

production quantity.Production rate• Production rate is the number of pieces that can be

produced per unit of time.Lead time• Lead time is the length of time between receipt of order

and delivery of product to customer.



Selection of Manufacturing Processes

• Some considerations are:1. Properties of the material2. Geometric features3. Dimensional-tolerance and surface-finish requirements4. Functional requirements of the part5. Production quantity required6. Costs



Manufacturing Costs and Cost Reduction

• The total cost of a product consists material, tooling, fixed, variable, direct and indirect labour costs.

• Costing has the following considerations:1. quality improvements and inventory reduction2. life-cycle costs3. machine usage4. purchasing cost5. financial risks



Manufacturing Costs and Cost Reduction

• Major cost factors are:1. Material costs2. Tooling costs 3. Fixed costs4. Capital costs5. Labour costs



Cost reduction

• Cost reduction requires assessment of costs that incurred and interrelated.

• An approximate breakdown of costs is

• Cost reductions can be achieved by:1. simplifying product design2. reducing the amount of materials3. investigating alternative methods4. using more efficient equipments