Chapter 12- Quality By Design

1. Chapter 12- Quality By Design • Introduction • Concurrent Engineering • Life-Cycle Costs and Engineering Changes • Quality Function Deployment • Design for Manufacture and Assembly • Taguchi Methods • Conclusion

2. Metrics for Design Quality • Percent of revenue from new products or services • Percent of products capturing 50% or more of the market • Percent of process initiatives yielding a 50% or more improvement in effectiveness • Percent of suppliers engaged in collaborative design

3. Concurrent Engineering • The Design Process • Life-Cycle Costs and Engineering Changes • What Concurrent Engineering Teams Do • Benefits of Concurrent Engineering • Concurrent Engineering Team Organization

4. What Concurrent Engineering Teams Do • Determine the overall character of the product, its design, and method of manufacture. • Perform product functional analysis. • Explore ways to improve producibility and usability. • Design a process for product assembly and production control, and design the parts of the product to be compatible with the assembly process. • Design the manufacturing processes for the product.

5. Benefits of Concurrent Engineering • Helps to understand the requirements of customers so that a better product acceptable to customers may be designed and made. • Product development time is reduced since design and process planning activities are completed simultaneously. • Design trade-offs, for example, between product features and production capabilities can be easily be facilitated with a view to improve the design.

6. Life-Cycle Costs and Engineering Changes Life-Cycle Costs - Costs incurred from cradle to grave - About 80% of product costs are committed in the design and development phase of a product. - Consequently, it is important to avoid mistakes early on in the design process. - The design and redesign process will require numerous engineering change orders that could be time consuming and lengthy. -

7. Fault Tree for Potato Chips

8. FAILURE MODE CAUSE OF FAILURE EFFECT OF FAILURE CORRECTIVE ACTION FMEA for Potato Chips

9. Value Analysis (Value Engineering) • Ratio of value / cost • Assessment of value : 1. Can we do without it? 2. Does it do more than is required? 3. Does it cost more than it is worth? 4. Can something else do a better job 5. Can it be made by less costly method, tools, material? 6. Can it be made cheaper, better or faster by someone else?

10. Design for Environment • Design from recycled material • Use materials which can be recycled • Design for ease of repair • Minimize packaging • Minimize material & energy used during manufacture, consumption & disposal

11. Design for Environment

12. Quality Function Deployment (QFD) • Developed by Mitsubishi’s Kobe Shipyard in 1972 and was adopted by Toyota 1978 • QFD is being used by numerous US companies now - This is a planning, communication, and documentation technique used to resolve design problems - Translates the “voice of the customer” into technical design requirements - Displays requirements in matrix diagrams - First matrix called “house of quality” - Series of connected houses

13. 5 Importance Correlation matrix 3 Design characteristics 4 2 1 Customer requirements Relationship matrix Competitive assessment Target values 6 6 House of Quality

14. Competitive Assessment Customer Requirements 1 2 3 4 5 Presses quickly 9 B A X Removes wrinkles 8 AB X Doesn’t stick to fabric 6 X BA Provides enough steam 8 AB X Doesn’t spot fabric 6 X AB Doesn’t scorch fabric 9 A XB Heats quickly 6 X B A Automatic shut-off 3 ABX Quick cool-down 3 X A B Doesn’t break when dropped 5 AB X Doesn’t burn when touched 5 AB X Not too heavy 8 X A B Irons well Easy and safe to use House of Quality Figure 3.8

15. Energy needed to press Weight of iron Size of soleplate Thickness of soleplate Material used in soleplate Number of holes Size of holes Flow of water from holes Time required to reach 450º F Time to go from 450º to 100º Protective cover for soleplate Automatic shutoff Customer Requirements Presses quickly - - + + + - Removes wrinkles + + + + + Doesn’t stick to fabric - + + + + Provides enough steam + + + + Doesn’t spot fabric + - - - Doesn’t scorch fabric + + + - + Heats quickly - - + - Automatic shut-off + Quick cool-down - - + + Doesn’t break when dropped + + + + Doesn’t burn when touched + + + + Not too heavy + - - - + - Irons well Easy and safe to use House of Quality

16. - - Energy needed to press Weight of iron Size of soleplate Thickness of soleplate Material used in soleplate Number of holes Size of holes Flow of water from holes Time required to reach 450º Time to go from 450º to 100º Protective cover for soleplate Automatic shutoff + + + House of Quality Figure 3.10

17. Design For Manufacturing and Assembly • Design Axioms • DFM Guide Lines • DFA Principles • Fully Exploiting DFMA

18. Taguchi Methods • Robust Design • Taguchi Approach to Design • Planned Experimentation • Design of Experiments • DOE and DFMA for Process Improvement • Orthogonal Arrays • Quality Loss • Criticism of Taguchi