Electronics Manufacturing – M528
Design and product quality
What is quality?
Images copyright (left to right) Freeplay Energy Group, OMRON Corp., Nintendo Corp. and Apple Corp.
Design is
fitness for purpose:
- Functionality
- Performance
- Aesthetics
- Skill level
Image copyright Segway Inc.Conflicts about purpose is often the primary cause of failed products.
Design is
fitness for standards:
- Based on inspection and measurement
- Six Sigma Quality
- ISO 9001:2000
Image copyright Princeton Digital Corp.Measurement of quality is dependent on the purpose.
- Time
- Functionality
- Material
- Process
- Cost
- Flexibility
Image copyright Acer Inc.
Design is
fitness for market:
- Satisfy user needs
- Industry structure and organizations
- Comparative cost
- Satisfy latent needs
Image copyright Sony Corp.Machines and processes may collect quality indicators or implement quality procedures, but people define and evaluate quality.
How do people identify quality?
- Are people consistent?
- Are people predictable?
- Are people political?
- Are people independent?
Where does quality come from?
Image copyright Dalsa Corp.
Can we have accidental quality?
Design is the source of quality.
Product design must factor an increasing number of requirements: (concurrent engineering)
- Use standard commercially available components.
- Use common parts where possible.
- Design for ease of component fabrication.
- Design components with tolerances that are within process capability.
- Design the product to be foolproof during assembly.
- Minimise flexible components.
- Design for ease of assembly.
- Design for ease of packaging.
- Minimise adjustments/calibrations.
Design and quality are affected by many factors:
- Delivery
- Installation
- Reliability
- Maintainability
- Serviceability
- Human factors
- Upgradeability
- Disposability
Design for assembly (DFA)
- Minimize parts count
- Encourage modular assembly
- Stack assemblies
- Eliminate adjustments
- Eliminate cables
- Use self-fastening parts
- Use self-locating parts
- Eliminate reorientation
- Facilitate parts handling
- Specify standard parts
Which products could be assembled using these principles?
How are conflicts in the rules resolved?
There are many methods to manage the quality of manufacturing:
Quality control
- Traceability
- Control of components
- Control of processing
- Points of inspection
- Assembly
Quality indicators
Sampling methods
- 100% inspection
- Statistical sampling
Output should be products without deficiencies:
- Absence of defects
- Conforms to specifications
- Components within tolerances
- No missing parts
- No early failures
Yield is quotient of good outputs to total outputs.
- Yield is critical for electronics manufacturing.
- Yield loss is due to systematic and random factors.
- Manufacturing is a statistical business, yield management is about reduction of loss.
What is the cost of quality?
Source: Gallien, J. (2002). Lecture for 15.760B course. MIT.
