3Chapter ObjectivesDescribe the phases or stages in systems engineering and the new product development processRecognize product liability and safety issuesRecognize the significance of reliability and other design factors
4Nature of Engineering Design Eng. Design ProcessInformation:Statement of the problemDesign standardsDesign methodsInformation:DrawingsSpecificationsFinancial estimatesWritten reportsOral presentations
5Systems Engineering/ New Product Development The design of a complex engineered system, from the realization of a need through production to engineering support in use is known as systems engineering (especially with military or space systems) or as new product development (with commercial systems).
6New Product Development - Stages ConceptualTechnical Feasibility or Concept DefinitionDevelopmentCommercial ValidationProductionProduct SupportDisposal Stage
7Systems Engineering Process (In each phase of development) Requirements Analysis: Analyze customer needs, objectives, and constraints to determine the functional requirements.Functional Analysis/Allocation Identify lower level functions needed to meet these functional requirements, and translate them into design requirements suitable as design criteria.Synthesis. Define the system concept, configuration item alternatives and select the preferred set of product or process solutions to the level of detail required in the phase being conducted.
8Systems Engineering Process (In each phase of development) System Analysis and Control. Provide the progress measurement, assessment, and decision mechanisms required to evaluate design capabilities and document the design and decision data.Trade-off (trade) studiesRisk managementConfiguration managementInterface managementSystems engineering master schedule (SEMS)Technical performance measurement (TPM)Technical (design) reviews
9Quality Function Deployment (QFD) Quality function deployment is a team-based management tool in which the customer expectations are used to drive the product development process.Conflicting characteristics or requirements are identified early in the QFD process and can be resolved before production.
10Quality Function Deployment (QFD) Key benefits:product improvement,increased customer satisfaction,reduction in the total product development cycle, &increased market share.
11QFD: House of Quality Interrelationship between Technical Descriptors How: Technical Descriptors(Voice of the Organization)What: Customer Reqmts(Voice of Customer)Relationship betweenRequirements and DescriptorsPrioritized Customer ReqmtsPrioritized Technical Descriptors
124 Phases of QFD Phase I: Product planning Phase II: Parts deployment Phase III:ProcessplanningPhase IV:Productionplanning
13Classical Model of QFD How What Matrix Voice of Customer House of QualityTech. Performance MeasuresPiece/Part CharacteristicsTech. Performance MeasuresSubsystem Design MatrixProcess ParametersPiece/Part CharacteristicsPiece/Part Design MatrixProduction OperationsProcess ParametersProcess Design Matrix
14Portable Slide Projector QFD Example:Portable Slide ProjectorEngineering MetricsBrightnessWeightDimensions (girth + width)Time/Tasks required to startDistortionDistance from presenterTime to insert/pull-out slideAttractive productCustomer NeedsGood imageEasy to transportKeeps present. flowingImage visible in bad conditionsMinimizes unplanned interruptionsDesign makes the product attractiveDevice sets up quicklyWorks well for short present.
15Portable Slide Projector—Phase I QFD Example:Portable Slide Projector—Phase IEngineering MetricsBrightnessWeightDimensionsTime/TasksDistortionDistanceTime to insert/pullAttractive productCustomerWeights913Customer RequirementsGood imageEasy to transportDevice sets up quicklyWorks well for short present.Keeps present. flowingImage visible in bad conditionsMinimizes unplanned interruptionsDesign makes the product attractive931Rawscore10811711481587227RelativeWeight16%17%12%8%11%4%
16Portable Slide Projector—Phase II QFD Example:Portable Slide Projector—Phase IIPart CharacteristicsTop caseBottomcaseLensCondenserStandHeat sinkLampRelativePhase IWeights16%17%13%8%10%4%Engineering MetricsBrightnessWeightDimensions (girth + width)Time/Tasks required to start pres.DistortionDistance from presenterTime to insert/pull-out slideAttractive product913Rawscore220.127.116.11.18.104.22.168Rel.Weight17%15%21%23%5%6%13%Rank3421765
17Phases in Systems Engineering / New Product Development (DoD) Pre-milestone zero studiesConcept exploration & definitionDemonstration and validationEngineering and manufacturing developmentProduction and deploymentOperations and support
18Phases in Systems Engineering / New Product Development (NASA) Conceptual design studiesConcept definitionDesign and developmentFabrication, integration, test, and certificationPre-operationsOperations and disposal
19Phases in Systems Engineering / New Product Development (NSPE/NIST ) ConceptualTechnical feasibilityDevelopmentCommercial validation and production preparationFull-scale productionProduct support
20Tasks Within Each Phases of Systems Eng. / New Product Development Approval to expend the resources / agreement on the work to be accomplished.Accomplishment of the workCompile the results: designs and specifications, analyses and reports, and a proposed plan for conducting the following phase if one is recommended.To cancel the development,To go back (recycle) and do more work in the present phase; orTo proceed with the next phase.
21Conceptual stageStatement of the design problem, clearly defining what the desired intended accomplishment of the desired productKey functionsPerformance characteristicsConstraintsCriteria of judging the design quality
22Conceptual stage Musts: requirements that must be met Must nots: constraints defining what the system must not be or doWants: features that would significantly enhance the value of the solution but are not mandatory (to which an additional, even less compelling category of "nice to have" is often added)Don't wants: characteristics that reduce the value of the solution
24Conceptual stage (Kano’s Model) DissatisfiersExpected QualityScratches, blemishesSmooth SurfaceBroken partsAll parts workMissing instructionClear instructionFunction not providedNormal functionProduct is unsafeProduct is safe to useProduct is non-conformantProduct conforms to std.
26Conceptual stage (Kano’s Model) Examples of DelightersSony Walkman3M Post-itCup HolderOne-touch recordingRedial button on telephoneGraphic User Interface (GUI)
27Results from Conceptual stage A set of functional requirementsIdentification of the potential barriers to development, manufacturing, and marketing the proposed product.Test-of-principle model to reduce technical uncertaintiesOrder-of-magnitude economic analyses andPreliminary market surveys to reduce financial uncertainty.
28Importance of Conceptual stage 1% of the cost of the product70 % of the life-cycle cost
29Technical feasibility stage The objectives of this stage areTo confirm the target performance of the new product through experimentation and/or accepted engineering analysis andTo ascertain that there are no technical or economic barriers to implementation
30Technical feasibility stage Subsystem identificationTrade-off studiesSystem integrationInterface definitionPreliminary breadboard-level testingSubsystem and system design requirements (reliability, safety, maintainability, and environmental impact).Development of preliminary test plans, production methods, maintenance and logistic concepts, and marketing plans.Preliminary estimation of the life-cycle cost of the system.Preparation of a proposal for the development stage
31Importance of Technical feasibility stage 7% of the cost of the product85 % of the life-cycle cost
32Development stage (Build-test-fix-retest sequences) The objective of this stage isTo make the needed improvements in materials, designs and processes andTo confirm that the product will perform as specified by constructing and testing engineering prototypes or pilot processes.
33Commercial validation and Production preparation stage The objective of this stage is to develop the manufacturing techniques and establish test market validity of the new product.Selecting manufacturing procedures, production tools and technology, installation and start-up plans for the manufacturing process, andSelecting vendors for purchased materials, components, and subsystems. Reproduction prototypes
34Full-scale production stage Final design drawings, specifications, flow charts, and procedures are completed for manufacture and assembly of all components and subsystems of the product, as well as for the production facility.Quality control procedures and reliability standards are establishedContracts made with suppliersProcedures established for product distribution and support.Manufacturing facilities are constructedContinuous process improvement (kaizen)
35Product support stageTechnical manuals for product installation, operation, and maintenanceTraining programs for customer personnelTechnical supportsWarranty servicesRepair parts and replacement consumables must be manufactured and distributedNew procedures for operation and maintenanceImproved parts for retrofitNotification of product recall for safety reasons
36Disposal stageEvery product causes waste during manufacture, while in use, and at the end of useful life that can create disposal problems.The time to begin asking, "how do we get rid of this" is in the early stages of product or process design.
38Traditional Product Development System Level DesignSubsystem DesignComponent DesignManufacturing Process Concept DevelopmentManufacturing Process DevelopmentDelivery DevelopmentService DevelopmentDelivery
39Concurrent Processes System Level Design Manufacturing Process Concept DevelopmentDelivery DevelopmentSubsystem DesignManufacturing Process DevelopmentService DevelopmentComponent DesignProduction & Delivery
40Definition of Concurrent Engineering A systematic approach to the integrated, concurrent design of products and their related processes, including manufacture and support.This approach is intended to cause the developer, from the outset, to consider all elements of the product lifecycle from concept through disposal, including quality control, cost, scheduling, user requirements. (Inst. For Defense Analysis)
41Advantages of Concurrent Engineering The set of methods, techniques, and practices that:Cause significant consideration within the design phases of factors from later in the life cycle;Produce, along with the product design, the design of processes to be employed later in the life of the product;Facilitate the reduction of the time required to translate the design into distributed products; andEnhance the ability of products to satisfy users' expectations and needs.
42CALS "Computer Aided Logistics Support," then "Computer-aided Acquisition and Logistics Support,""Continuous Acquisition and Life-Cycle Support," (1993, DoD)"Commerce At Light Speed" (U.S. industry)
43Purposes of CALSTo enable more effective generation, management, and use of digital data supporting the life cycle of a product through the use of international standards, business process change, and advanced technology application.
44CALS Electronic storage, transmission, and retrieval of digital data Between engineers representing the several design stages,Between organization functions such as marketing, design, manufacturing, and product support, andBetween cooperating organizations such as customer and supplier.
45Commercial standardsComputer Graphics Metafile (CGM) (ISO-8632): A standard means of representing line drawings in a device-independent way.Electronic Data Interchange for Administration, Commerce, and Transport (EDIFACT) (ISO 9735, ANSI X12): An international standard means for communicating commercial (trade) information.Initial Graphics Exchange Specification (IGES) (ANSI Y14.26M): A standard means of representing product data in a device-independent way.
46Control Systems in Design Drawing/Design ReleaseVersion ControlProduct Data Management (PDM)Configuration (Design Criteria) ManagementFunctional baseline (at end of conceptual stage)Allocated baseline (at end of validation stage)Product baseline (at end of development stage)Design Review
47Special Considerations in Design Product liabilitySafetyReliabilityMaintainabilityAvailabilityErgonomicsProducibility
48History of Product Liability Caveat emptor (let the buyer beware)“Privity of contract” (Direct contractual relationship)1916, MacPherson v. Buick (No need for direct contract)Plaintiff must prove negligence1960, Hernington v. Bloomfield Motors, implied warranty1984, Greenman v. Yuba Power Product Strict LiabilityAbsolute liability: “A manufacturer could be held strictly liable for failure to warn of a product hazard, even if the hazard was scientifically unknowable at the time of the manufacture and sale of the product.”
49Reducing LiabilityInclude safety as a primary specification for product design.Use standard, proven materials and components.Subject the design to thorough analysis and testing.Employ a formal design review process in which safety is emphasized.Specify proven manufacturing methods.Assure an effective, independent quality control and inspection process.Be sure that there are warning labels on the product where necessary.
50Reducing LiabilitySupply clear and unambiguous instructions for installation and use.Establish a traceable system of distribution, with warranty cards, against the possibility of product recall.Institute an effective failure reporting and analysis system, with timely redesign and retrofit as appropriate.Document all product safety precautions, actions, and decisions through the product life cycle.
51Designing for Reliability Definition of Reliability:Reliability is the probability that a systemWill demonstrate specified performanceFor a stated period of timeWhen operated under specified conditions.
52Reliability Measures Reliability Failure CDF (cumulative distribution function):Failure PDF (probability density function):Failure or hazard rate:
53Simple Reliability Models Simple Series ModelSLSimple Parallel ModelL
56Designing for Reliability “Start with the best”RedundancyFactor of safety
57MaintainabilityMaintainability is the probability that a failed systemWill be restored to specified performanceWithin a stated period of timeWhen maintained under specified conditions.
58Maintainability Maintenance downtime Administrative & preparation time Logistic timeActive maintenance timeTypes of MaintenanceCorrective maintenancePreventive maintenancePredictive maintenance
59AvailabilityInherent Availability (considers only corrective maintenance)Ai = MTBF / (MTBF+MTTR)Operational Availability (considers both preventive & corrective maintenance)Ao = MTBM / (MTBM+MDT)MTBM: Mean Time Between MaintenanceMDT: Mean Down TimeMTTR: Mean Time To RepairMTBF: Mean Time Between Failure (1/)BIT: Build-In Test
60Other Considerations Human Factors Engineering (Ergonomics) StandardizationSet of specifications for parts, materials, or processes intended to achieve uniformity, efficiency, and a specified quality.Producibility
61Value EngineeringA methodical study of all components of a product in order to discover and eliminate unnecessary costs over the product life cycle without interfering with the effectiveness of the product.What is it?What does it do?What does it cost?What does it worth?What else might do the job?What do the alternatives cost?Which alternative is least expensive?Will the alternative meet the requirements?What is needed to implement the alternative?