最佳化设计方式_Design for eXcellence

Old “over-the-wall” sequential products design process
* Each function did its work and
passed it to the next function
Improved Concurrent Engineering process
Reliability
EML4550 -- 2007
Design for Reliability (DFR)
Design for Supply Chain (DFSC)
BOM Health Check
Rapid Changes New products rapidly introduced Short, unknown product life cycles High Variety of Products Long Production Lead Times Increasing storage and transportation costs Difficult to forecast demand
Design for eXcellence
Chiu
目錄
Ability to Impact Product Value Design for Reliability (DFR) Design for Supply Chain (DFSC) PCB Design Engagement Design for Assembly (DFA) Design for Reliability (DFR) Design for Testability (DFT)
Design for Supply Chain ?
Strategic Operational Supply Ta c t i c a l
Production
Distribution
Demand
Supply Chain Design allows companies to thrive since it optimizes the terrain in which planning and execution is in control. A roadmap is then crafted based on this and suggested for improvement, always to be observed within the following in three capabilities technology,people, process. • Technology limits the following: • Depth of studies • Variety of studies • Visibility • Speed of process and response • Flexibility • Training, Standardization, growth speed • Opportunities in developing training, growth plans,career paths, COE build up and renewal • Opportunity in building COE Supply Chain DesignR&D • Automation & Standardization, possibility of easily sharing knowledge and leveraging people.
TESTABILITY
PERFORMANCE
AREA
Ability to Impact Product Value
Total cost
Minimized cost
Cost
Cost due to design and manufacture Cost to customer: failed products, reputation, etc..
Pa
P - probability of a defect n - number of defects Pa - probability of accepting a bad product
n
Y (1 P)
- probability of producing a good product
Fault Modeling Identify target faults Limit the scope of test generation Make analysis possible Test Generation Automatical or Manual Fault Simulation Assess completeness of tests Testability Analysis Analyze a circuit for potential problem on test generation Design For Testability Design a circuit for guaranteed test generation Introduce both area overhead and performance degradation
DFX Design for eXcellence
* Design for Supply Chain (DFSC) * Process of ensuring material sourcing, supply, compliancy and lifecycle requirements
are met during design stage.
Responsiveness Competitive pricing Efficiency Customer service
Product and process design key cost drivers of product
cost
Design for Manufacturing used design to decrease
* All functions form a design team
that develops specifications, involves customers early, solves potential problems, reduces costs, & shortens time to market
The Infamous Design/Test Wall
30 years of experience proves that test after design does not work!
Oh no! What does this chip do?!
Functionally correct! We're done!
* Design for Manufacturability (DFM) * Process of ensuring the manufacturability of a component or complete assembly to
met supplier’s capability.
* Design for Test (DFT) * Process of analyzing test access, coverage and schematics are designed for test
PCB Design Engagement
Design for Assembly (DFA)
Design for Reliability (DFR)
Design for Reliability (DFR)
Derating Curve
Failure Rate of a gear:
λb= base failure rate specified by the manufacturer s = operating speed sd= design speed L = operating load Ld= design load v = viscosity of lubricant used vs= viscosity of specification lubricant c = concentration of contaminants cs=standard contamination level T = operating temperature Ts= specification temperature
Concerned when abnormal loads are possible Probabilistic compare the magnitude of the stress with the design strength. Use physical models Major categories of stresselectrical thermal mechanical chemical Two design approaches select parts with sufficient strength against max load protect part against excessive stresses
manufacturing costs

Major supply chain costs include transportation costs,
inventory costs, distribution costs logistics costs
Design for Logistics uses product design to address Key Concepts of Design for Logistics Economic packaging and transportation Concurrent/Parallel Processing Standardization
cost drivers are met.
* Design for Assembly (DFA) * Process of ensuring the assembly of the PCB design and physical layout rules are met
prior to prototype
Electronic Circuit Boards
Design for Testability (DFT)
The problem is - QUALITY:
Yield (Y)
P,n Design for testability Testing Defect level (DL) Quality policy
* Design for Reliability (DFR) * Process for ensuring reliability of a product or system during the design stage
beforephysical prototype
* Design for Fabrication (DFF) * Process of ensuring the manufacturability of the PCB fabrication design and related
Design Engineering
Test Engineering
* Design circuit to optimally satisfy or trade-off
their design constraints in terms of area, performance and testability.