Design ConcernsDesign Concerns

IN DEVELOPING DESIGN CONCERNS THE IN DEVELOPING DESIGN CONCERNS THE FOLLOWING PRODUCT FOLLOWING PRODUCT ATTRIBUTES/FEATURES SHOULD BE ATTRIBUTES/FEATURES SHOULD BE CONSIDEREDCONSIDERED

PhysicalPhysical StructuralStructural EnvironmentalEnvironmental Human engineeringHuman engineering Life cycleLife cycle CostCost

PHYSICALPHYSICAL

Configuration/sizeConfiguration/size– Dimensions (can bound if unable to define exactly - not Dimensions (can bound if unable to define exactly - not

less than/not greater than)less than/not greater than)– TolerancesTolerances– Surface finishesSurface finishes

WeightWeight Mass propertiesMass properties

– Center of gravityCenter of gravity– Moments of inertiaMoments of inertia

STRUCTURALSTRUCTURAL

Need to consider piece parts and assemblies (joining Need to consider piece parts and assemblies (joining mechanisms)mechanisms)

StrengthStrength StiffnessStiffness ImpactImpact Durability (fatigue)Durability (fatigue)

ENVIRONMENTALENVIRONMENTAL

In-service conditionsIn-service conditions Temperature, humidity, UV exposure, chemical Temperature, humidity, UV exposure, chemical

exposureexposure

HUMAN ENGINEERINGHUMAN ENGINEERING

SafetySafety ErgonomicsErgonomics AestheticsAesthetics

LIFE CYCLELIFE CYCLE

"Cradle-to-grave“"Cradle-to-grave“ Sustainability, “Green”Sustainability, “Green”

– Maintenance, repairabilityMaintenance, repairability– Renewable materialsRenewable materials– Disposal (recyclable, biodegradable, hazardous Disposal (recyclable, biodegradable, hazardous

materials)materials) WarrantyWarranty

COSTCOST

Cost (materials, manufacturing process - labor, Cost (materials, manufacturing process - labor, tooling, equipment usage)tooling, equipment usage)

Additional considerations Additional considerations – Price (look at competing products to gain insight)Price (look at competing products to gain insight)– ProfitProfit

ASSUME THE NEED IS A COMMUTER ASSUME THE NEED IS A COMMUTER BICYCLEBICYCLE

Translating customer input into quantifiable design Translating customer input into quantifiable design concernsconcerns– Physical - lightweightPhysical - lightweight– Structural - adequate strengthStructural - adequate strength– Environmental - will not degrade when exposed to waterEnvironmental - will not degrade when exposed to water– Human engineering - accessibility to controlsHuman engineering - accessibility to controls– Life cycle - easy to serviceLife cycle - easy to service– Cost - affordable priceCost - affordable price

DETERMINING ASSESSMENT DETERMINING ASSESSMENT MEASURES FOR EACH DESIGN MEASURES FOR EACH DESIGN CONCERNCONCERN

Definition: what will be measured to determine how the Definition: what will be measured to determine how the design performs with respect to the specific design design performs with respect to the specific design concern (note units)concern (note units)

Requirement: if the design concern is a requirement, what Requirement: if the design concern is a requirement, what is the level (value) of the assessment measure which has is the level (value) of the assessment measure which has to be achieved in order to comply with the requirement (for to be achieved in order to comply with the requirement (for a design concept to be considered a possible solution)a design concept to be considered a possible solution)

Goal: if the design concern is a goal, what is the desired Goal: if the design concern is a goal, what is the desired direction of the assessment measure in order to come direction of the assessment measure in order to come closer to achieving the goal (the design concept which closer to achieving the goal (the design concept which performs most favorably with respect to the goals is the performs most favorably with respect to the goals is the best solution)best solution)

For the bicycle exampleFor the bicycle exampleMicrosoft Office Excel Worksheet