Presentation on theme: "INSE 6411 Product Design Theory and Methodology"— Presentation transcript:
1 INSE 6411 Product Design Theory and Methodology Product Architecture and Design for XLecture 9Andrea Schiffauerova, PhD.
2 Product architectureProduct architecture is the assignment of the functional elements of a product to the physical building blocks of the product.The functional elements are the individual operations and transformations (expressed by VERBS)The physical elements of a product are the parts, components, and subassembliesThe physical elements of a product are typically organized into several major physical building blocks, called chunks.The purpose of the product architecture is to define the basic chunks in terms of what they do and what their interfaces are
3 Modular product architecture Each chunk fully embodies one or more product functions.Interactions between chunks are:well defined(typically) fundamental to product‘ primary functions.Advantages:simplicityreusability for a product family or platform.easier design changes
4 Integral product architecture Typical functions involve more than one chunkTypical chunks implement more than one functionInteractions between chunks are ill-defined and may be incidental to product's primary functions.Advantages:increased performancereduced costs for any specific product model.However:it may require extensive redesign of the product if a design change is made
5 Modular architecture Example: Trailer Physical chunks: Product functions:boxprotect cargofrom weatherhitchconnect to vehiclefairingminimize air dragbedsupportcargo loadsspringssuspend trailer structurewheelstransfer loads to road
6 Integral architecture Example: Trailer Physical chunks: Product functions:upper halfprotect cargofrom weatherlower halfconnect to vehiclenose pieceminimize air dragcargo hanging strapssupportcargo loadsspring slotcoverssuspend trailer structurewheelstransfer loads to road
7 Product architectureModular or integral architecture?
8 Modularity - types Modularity is a relative property Products are rarely strictly modular or integral.Slot-modular architectureEach chunk-to-chunk interface is different from the others.Chunks cannot be swapped around.Ex.: automobile radio, speedometerBus-modular architectureUses a common bus, or similar concept.Uses standard chunk-to-bus interfaces.Ex.: expansion card for PCSectional-modular architectureNo common bus or other single element interfacing with all other chunks.Uses standard chunk-to-chunk interfaces.Ex.: sectional sofa, office partitions, piping systems
9 Product architecture selection Architecture decisions relate to product planning and concept development decisions:Product changeProduct varietyStandardizationPerformanceManufacturing costProject managementSystem engineering
10 Establishing the architecture Create a schematic illustrating product architectureCluster elementsIdentify fundamental and incidental interactions
11 1. Create a schematic DeskJet Printer Schematic Enclose Printer Print CartridgeProvideStructuralSupportAcceptUserInputsDisplayStatusPositionCartridgeIn X-AxisStore OutputPositionPaperIn Y-AxisControlPrinterSupplyDCPowerStore Blank Paper“Pick”PaperCommunicatewithHostCommandPrinterFunctionalor PhysicalElementsFlow of forces or energyFlow of materialFlow of signals or dataConnecttoHost
13 2. Cluster elements into chunks Key considerations when clustering elements (of schematic) into chunks include:Geometric integration and precisionEx.: H-P clustering for ink-jet printer calls for cartridge positioning on x-axis and paper positioning on y-axisFunction sharingEx.: Status display and user controls for H-P printerVendor (= Supplier) capabilitiesSimilarity of design or production technologyLocation of changeAccommodating varietyEnabling standardization
14 3. Incidental interactions Identification of interactions between chunks:Fundamental interactionsPlanned, well understood interactionsEx.: H-P printer: Sheets of paper flow from the paper tray to print mechanism.Incidental interactionsArise due to the implementation of elementsEx.: H-P printer: Vibration induced by the actuators in paper tray may interfere with precision positioning of print cartridge (x-axis)
16 Delayed differentiation Product architecture can be a key determinant of the performance of the supply chainDelayed differentiation is postponing the differentiation of a product until late in the supply chainMay offer substantial reductions in the costs of operating supply chain, primarily through the reductions in inventory requirements.
19 Design for XDesign for X summarizes a wide collection of specific design guidelines.X = quality criteriaDesign for ManufacturingDesign for AssemblyDesign for ReliabilityDesign for TestingDesign for MaintenanceDesign to CostDesign for Value
20 Design for Manufacturing Widely usedPoorly defined (the definition may include various practices)DFM is establishing the shape of components for efficient, high-quality manufacturingKey concerns:Specifying the best manufacturing process for each component:Ensuring that the component form supports the manufacturing process selectedFor each manufacturing process there are design guidelines that result in consistent components and little waste
21 Design for AssemblyDFA is the best practice used to measure the ease with which the product can be assembledDFM focuses on making the components and DFA is concerned with putting them togetherDFA measures a product in terms of the efficiency of its overall assembly and the ease with which components can be retrieved, handled and mated.Retrieval of the components from storageHandling the components to orient themMating the components (bringing them together)
22 Design for Assembly Old seat frame Redesigned seat frame 9 components 20 operations30 min to assemble4 components8 operations8 min to assemble
23 Design for Assembly Meaningful only for mass produced products! Expensive tooling is justified only if spread over a large manufacturing volumeIn low volume products there is a little payback for changing a design for easier assembly (the cost of assembly is only 1-5% of the total manufacturing cost)13 DFA guidelines to make products as easy to assemble as possible
24 Nail clipper with one interface Design for AssemblyGuideline 1: Minimize overall component countExamine each pair of adjacent components and determine whether they have to be separate (to operate mechanically, different materials, etc.)Common nail clipperNail clipper with one interfacefor each functionA one-piece nail clipper
25 A single base for locating Design for AssemblyGuideline 2: Make minimum use of separate fastenersEach fastener is one more component to handleEvery fastener adds costsFasteners are stress concentratorsGuideline 3: Design the product with a base component for locating other componentsA single base on which all other components are assembledA single base for locatingother components
26 Design for AssemblyGuideline 4: Do not require the base to be repositioned during assemblyRepositioning may be time consuming and costly (especially on larger products)Guideline 5: Make the assembly sequence efficientAn efficient assembly sequence:Involves only few stepsAvoids risk of damaging componentsAvoids awkward or unstable positionsAvoids creating many disconnected subassemblies
27 Design for Assembly Guideline 6: Modificationsto avoid tanglingGuideline 6:Avoid component characteristics that complicate retrievalTangling
28 Design for AssemblyNestingModifications to avoid nesting
29 Modification of parts for end-to-end symmetry Design for AssemblyGuideline 7: Design components for a specific type of retrieval, handling and matingManual assembly (less than products annually)Robot assembly (up to 2 million annually)Special-purpose machines (more than 2 millions annually)Modification of parts for end-to-end symmetryGuideline 8: Design all components for end-to-end symmetryEnd-to-end symmetry is a symmetry about an axis perpendicular to the axis of insertion – a component can be inserted in the assembly either end first
30 Design for AssemblyGuideline 9: Design all components for symmetry about their axes of insertionStrive for axis-of-insertion symmetry (rotational symmetry)Modification of features for symmetry about the axis of insertion:Adding a functionally useless notchAdding a hole and rounding the end
31 Design for AssemblyModification of a part for symmetry
32 Modification of parts to force asymmetry Design for AssemblyModification of parts to force asymmetryGuideline 10: Design components that are not symmetric about their axes of insertion to be CLEARLY asymmetricMake components that can be inserted only in the way intended (easy orientation)
33 Design for AssemblyGuideline 11: Design components to mate through straight-line assemblyTo minimize the motions of assemblyNo reorientation of the baseAll the motions are straight downOne-direction assembly
34 Design for AssemblyUse of chamfers (rounded corners) to ease assemblyGuideline 12: Make use of chamfers, leads and compliance to facilitate insertion and alignmentEach component should guide itself into place
35 Design for Assembly Use of leads to ease assembly Use of compliance to ease assembly
36 Design for Assembly Guideline 13: Maximize component accessibility Assembly can be difficult if components have no clearance for graspingAssembly efficiency is low if a component must be inserted in an awkward spotModification for tool clearance to ease assembly
37 Design for Reliability Reliability is a measure of how the quality of a product is maintained over timeFailure is an unsatisfactory performanceMethods:Failure Mode and Effects Analysis (FMEA)Helps in identifying the failures, their causes and the corrective actionsFault Tree Analysis (FTA)Helps in finding failure modesGraphically shows all the potential faults and their relationshipsMean Time Between Failures (MTBF)Average time elapsed between failures
38 Design for Maintenance Design for TestingTestability is the ease with which the performance of critical functions is measuredDesign for MaintenanceMaintainability or serviceability or reparability describe the ease of diagnosing and repairing the product
39 Design for Environment Green design or environmentally conscious design or life-cycle design or design for recyclabilityAfter a product’s useful life, the components are disposed (1970s and 1980s), reused or recycled (more and more nowadays)Why?EconomicsCustomer expectationGovernment regulations
40 Design to CostDesign to Cost is a process that constrains design options to a fixed cost limit.The cost limit is usually what the buyer can pay or what the marketplace demands.An affordable product is obtained by treating target cost as an independent design parameter that needs to be achieved during the development.
41 Design for ValueValue engineering is a customer-oriented approach to the entire design processThe focus changes from the cost of a component to its value to the customerValue is function provided per dollar of costCompare worth to cost to identify features that have low and high relative values
42 Next lecture Project management Product development economics Intellectual property rightsRobust design
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