Chapter 5
Product and Service
Design
Product Design
nSpecifies materialsnDetermines dimensions & tolerances
nDefines appearance
nSets performance standards
Service Design
Specifies what the customer is to experience
–physical items –sensual benefits –psychological benefits
An Effective Design Process
nMatches product/service characteristics withcustomer needs
nMeets customer requirements in simplest, most cost-effective manner
nReduces time to market
nMinimizes revisions
Breaking Down Barriers
Stages In The Design Process
nIdea Generation –Product Concept nFeasibility Study –Performance Specifications nPreliminary Design –Prototype nFinal Design
–Final Design Specifications
nProcess Planning
No Idea generation Final design Preliminary design Feasibility study Process planning Product feasible? Yes Prototype Manufacturing Design & Manufacturing
Specifications
The Design Process
Idea Generation
nSuppliers, distributors, salespersons
nTrade journals and other published material
nWarranty claims, customer complaints, failures
nCustomer surveys, focus groups, interviews
nField testing, trial users
nResearch and development
More Idea Generators
nPerceptual Maps–visual comparison of customer perceptions nBenchmarking
–comparing product/service against best-in-class
nReverse engineering
–dismantling competitor’s product to improve your own product
Perceptual Map Of Breakfast
Cereals
Good taste Bad taste High nutrition Low nutrition •Cocoa Puffs •Rice Krispies •Wheaties •Cheerios •Shredded WheatFeasibility Study
nMarket Analysis nEconomic AnalysisnTechnical / Strategic Analysis
Preliminary Design
nCreate form & functional designnBuild prototype
nTest prototype
nRevise prototype
Form Design
(How The Product Looks)
Functional Design
(How The Product Performs)
nReliability
–probability product performs intended function for specified length of time
nMaintainability
–ease and/or cost or maintaining/repairing product
Computing Reliability
0.90 0.90 .95 .90 0.90 x 0.90 = 0.81 1 - (1-0.90)(1-0.95) = 0.995 Components in series Components in parallelFinal Design & Process Planning
nProduce detailed drawings & specificationsnCreate workable instructions for manufacture
nSelect tooling & equipment
nPrepare job descriptions
nDetermine operation & assembly order
nProgram automated machines
Distribution Of Design Changes
21 12 3 Production 3
begins Months
Number of Design Changes
Company 2
90% of Total changes complete Company 1
Improving The Design Process
1. Design teams 2. Concurrent design
3. Design for manufacture & assembly 4. Design for environment
5. Measure design quality
6. Utilize quality function deployment 7. Design for robustness
Design Teams
nMarketing, manufacturing, engineeringnSuppliers, dealers, customers
nLawyers, accountants, insurance companies
Concurrent Design
Customers Marketing Design Engineering Suppliers ProductionConcurrent Design
nAlso, simultaneous or concurrent engineering
nSimultaneous decision making by design teams
nIntegrates product design & process planning
nDetails of design more decentralized
nEncourages price-minus not cost-plus pricing
nNeeds careful scheduling - tasks done in parallel
General Performance
Specifications
nInstructions to supplier:– “Design a set of brakes that can stop a 2200 pound car from 60 miles per hour in 200 feet ten times in succession without fading. The brakes should fit into a space 6” x 8” x 10” at the end of each axle and be delivered to the assembly plant for $40 a set.” nSupplier submits design specifications and
prepares a prototype for testing.
Role Of Design Engineer
nNo longer totally responsible for productdesign
nResponsible for more than what was traditionally considered “design”
nMerging of design engineer and manufacturing engineer
Design For Manufacture
nDesign a product for easy & economical production
nConsider manufacturability early in the design phase
nIdentify easy-to-manufacture product-design characteristics
nUse easy to fabricate & assemble components
DFM Guidelines
1. Minimize the number of parts 2. Develop a modular design 3. Design parts for multi-use 4. Avoid separate fasteners 5. Eliminate adjustments 6. Design for top-down assembly
7. Design for minimum handling 8. Avoid tools
9. Minimize subassemblies 10. Use standard parts when possible 11. Simplify operations
12. Design for efficient and adequate testing 13. Use repeatable & understood processes 14. Analyze failures
15. Rigorously assess value
Design Simplification
(a) The original design (b) Revised design (c) Final design
Design for push-and-snap assembly One-piece base &
elimination of fasteners Assembly using
common fasteners
More Design Improvements
nStandardization–uses commonly available parts –reduces costs & inventory nModular design
–combines standardized building blocks/modules into unique products
Design For Assembly (DFA)
nProcedure for reducing number of partsnEvaluate methods for assembly
nDetermine assembly sequence
Analyzing Failures
nFailure Mode and Effects Analysis (FMEA)
–a systematic approach for analyzing causes & effects of failures
–prioritizes failures –attempts to eliminate causes nFault Tree Analysis (FTA)
Failure Mode & Effects Analysis
Failure Mode Causes of Failure Effects of Failure Corrective Action Stale Low moisturecontent, expired shelf life, poor packaging
Tastes bad, won’t crunch, thrown out, lost sales
Add moisture, cure longer, better package seal, shorter shelf life Broken Too thin, too brittle,
rough handling, rough use, poor packaging
Can’t dip, poor display, injures mouth, choking, perceived as old, lost sales Change recipe, change process, change packaging
Too Salty Outdated recipe, process not in control, uneven distribution of salt
Eat less, drink more, health hazard, lost sales
Experiment with recipe, experiment with process, introduce low salt version
Fault Tree For Potato Chips
And Or
Value Analysis (Engineering)
nRatio of value / costnAssessment 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?
Design For Environment
nDesign from recycled materialnUse materials which can be recycled
nDesign for ease of repair
nMinimize packaging
nMinimize material & energy used during manufacture, consumption & disposal
Measures Of Design Quality
1. Number of component parts and product options 2. Percentage of standard parts
3. Use of existing manufacturing resources 4. Cost of first production run
5. First six months cost of engineering changes 6. First year cost of field service repair 7. Total product cost
8. Total product sales 9. Sustainable development
Quality Function Deployment
(QFD)
nTranslates the “voice of the customer” into technical design requirements
nDisplays requirements in matrix diagrams
nFirst matrix called “house of quality”
House Of Quality
6. Technical assessment and target values 1. Customer requirements 4. Relationship matrix 3. Product characteristics Importance 2. Competitive assessment 5. Tradeoff matrix
House Of Quality For Steam Iron
Series Of QFD Houses
Classical Models of QFD
Production Operations Process Parameters Process Design Matrix Process Parameters Piece/Part Characteristics Piece/Part Design Matrix Piece/Part Characteristics Tech. Performance Measures Subsystem Design Matrix Tech. Performance Measures Voice of Customer House of Quality How What Matrix
Management & Planning Tools
for QFD
nAffinity Diagram (Idea grouping)
nTree Diagram (Hierarchical structure)
nMatrix Diagram (¥=9, •= 3, r=1)
nPriotization Matrix (Weighted)
Customer Needs
nCustomer NeedsnImportance to the Customer
– Absolute Importance – Relative Importance – Ordinal Importance (ranking)
The Planning Matrix
nCurrent satisfaction performancenCompetitive satisfaction performance
nGoal
nImprovement ratio = Goal / Current S. P.
nSales point (1= no change, 1.2 = medium, 1.5 = strong)
nRaw weight = Importance x Imp. Ratio x S.P.
nNormalized raw weight = R.W. / ΣR.W.
Substitute Quality Characteristics
(Technical Response)
nPerformance Measurements
nProduct Functions
Impacts, Relationships, & Priorities
nAmount of Impact – ¥ Strongly linked = 9, – • Moderately linked = 3 – r Possibly linked = 1 nPriorities of SQC (ΣImpacts) nNegative Impacts
Technical Correlations
nüü : Strong positive impact nü : Moderate positive impactnBlank: No impact
nû : Moderate negative impact
nûû : Strong negative impact nçè Direction of impact
Technical Benchmarks
nBenchmarking performance measuresnBenchmarking functionality
– Competitive Benchmarks – Own Performance – Targets
Benefits Of QFD
nPromotes better understanding of customerdemands
nPromotes better understanding of design interactions
nInvolves manufacturing in the design process
nBreaks down barriers between functions and departments
nFocuses the design effort
nFosters teamwork
nImproves documentation of the design and development process
nProvides a database for future designs
nIncreases customer satisfaction
nReduces the number of engineering changes
nBrings new designs to the market faster
nReduces the cost of design and manufacture
Design For Robustness
nProduct can fail due to poor design qualitynProducts subjected to many conditions
nRobust design studies
–controllable factors - under designer’s control –uncontrollable factors - from user or environment nDesigns products for consistent performance
Consistency Is Important
nConsistent errors are easier to correct thanrandom errors
nParts within tolerances may yield assemblies which aren’t
nConsumers prefer product characteristics near their ideal values
Technology In Design
nCAD - Computer Aided Design–assists in creating and modifying designs nCAE - Computer Aided Engineering
–tests & analyzes designs on computer screen nCAD/CAM - Design & Manufacturing
–automatically converts CAD data into processing instructions for computer controlled equipment
Benefits Of CAD
nProduces better designs faster
nBuilds database of designs and creates documentation to support them
nShortens time to market
nReduces time to manufacture
nEnlarges design possibilities
nEnhances communication and promotes innovation in design teams
Characteristics Of Services
1. Intangible 2. Variable output 3. High customer contact 4. Perishable
5. Service inseparable from delivery 6. Decentralized
7. Consumed more often 8. Easily emulated
Service Design
Performance Specifications Design Specifications Delivery SpecificationsA Well-designed
Service System Is
nConsistent with firm’s strategic focusnUser friendly
nRobust
nEasy to sustain
nEffectively linked between front & back office
nCost effective
