Presentation on theme: "Engineering Design GE121 Finding Answers to the Problem Part III / IV"— Presentation transcript:
1 Engineering Design GE121 Finding Answers to the Problem Part III / IV Lecture 12A
2 Limiting Design Space to a Usable Size Pragmatic (practical) issues related to how an artifact will be used, and how it will be madeProvides ‘guideposts’ for development of the search space – may narrow rather than expand the search spaceDesign alternatives must be functions ofUser NeedsAvailable TechnologiesExternal Constraints(and some common sense!)
3 Limiting Design Space to a Usable Size (Continued) Example – Design of vehicles for a campus transportation systemCandidate VehiclesSimple bikesHigh Tech bikesRecumbent bikesTricyclesRickshawsUser Needs may dictate consideration of:Parking availabilityCarrying PackagesAccess for Handicapped
4 Limiting Design Space to a Usable Size (Continued) Available Technologies may affect design alternatives:Materials (affects appearance, manufacturing, price)External Constraints may limit design alternatives:Team’s area of expertise (may be expert in tricycle design)Available Manufacturing Facilities (may dictate material)Practical Considerations – Common Sense!Invoke and apply constraints (similar to user needs, as above)Freeze the number of attributes (avoid those unlikely to seriously affect design – i.e. color)Impose some order on the list (which functions / features are most important)Get Real! (watch out when silly / infeasible options are repeated too often)
5 Morphological Charts: Organizing Functions and Means to Generate Designs that Work Morphological Charts - Important Alternative Development toolsChart or MatrixFunctions or Key Features are listed in the first columnAlternate Means of achieving each function are given in that function’s rowGenerating the Means for each function can be a highly creative processMeans do not have to be Words – some designers use sketches or thumbnails to show some alternative means
6 Morphological Charts (continued) The Morphological Chart can be used to generate Complete AlternativesLeftmost column lists ALL functionsSelecting a means from EACH row guarantees that the solution satisfies all required functionalityWill NOT, however, guarantee thatAlternatives will WORKOr even be internally consistent (see Fig. 5.2b)Judgement is still requiredThis approach can result in a HUGE number of alternativesThe morph chart in Fig 5.2 can be used as an example of internal consistency and judgement. If “glass” is the selected material, then “box” and “bag” aren’t consistent containers. If “bottle” is the container, then “waxed cardboard” and “lined cardboard” are not good choices for material.
7 Morphological Charts (continued) Start with FunctionsContain BeverageMaterial for Beverage ContainerProvide Access to JuiceDisplay Product InformationSequence Manufacture of Juice and Container
8 Morphological Charts (continued) Add Means for Each FunctionContain Beverage: Can, Bottle, Bag, BoxMaterial for Beverage Container: Aluminum, Plastic, Glass, Waxed Cardboard, Lined Cardboard, Mylar FilmsProvide Access to Juice: Pull-Tab, Inserted Straw, Twist-Top, Tear Corner, Unfold Container, ZipperDisplay Product Information: Shape of Container, Labels, Color of MaterialSequence of Manufacture: Concurrent , Serial
9 Morphological Charts (continued) Create Morph Chart (words)Work through this example on inconsistencies such as “glass-bag” or judgements such as “bottle-waxed cardboard”.There are obvious combinations that can be eliminated: such as “can-tear corner” and “bottle-unfold container”. However, thinking about unlikely combinations may spark creative ideas.An implicit assumption in this chart is that the whole container must be made out of the same material (except for the mechanism for opening). Frozen juice concentrates have lined cardboard sides and metal lids. Is that (or another combination) feasible here?Fig. 5.1 p104Or – Use Thumbnails (next page)
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