Design Concerns

IN DEVELOPING DESIGN CONCERNS THE FOLLOWING PRODUCT ATTRIBUTES/FEATURES SHOULD BE CONSIDERED Physical Physical Structural Structural Environmental Environmental Human engineering Human engineering Life cycle Life cycle Cost Cost

PHYSICAL Configuration/size Configuration/size –Dimensions (can bound if unable to define exactly - not less than/not greater than) –Tolerances –Surface finishes Weight Weight Mass properties Mass properties –Center of gravity –Moments of inertia

STRUCTURAL Need to consider piece parts and assemblies (joining mechanisms) Need to consider piece parts and assemblies (joining mechanisms) Strength Strength Stiffness Stiffness Impact Impact Durability (fatigue) Durability (fatigue)

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

HUMAN ENGINEERING Safety Safety Ergonomics Ergonomics Aesthetics Aesthetics

LIFE CYCLE "Cradle-to-grave“ "Cradle-to-grave“ Sustainability, “Green” Sustainability, “Green” –Maintenance, repairability –Renewable materials –Disposal (recyclable, biodegradable, hazardous materials) Warranty Warranty

COST Cost (materials, manufacturing process - labor, tooling, equipment usage) Cost (materials, manufacturing process - labor, tooling, equipment usage) Additional considerations Additional considerations –Price (look at competing products to gain insight) –Profit

ASSUME THE NEED IS A COMMUTER BICYCLE Translating customer input into quantifiable design concerns Translating customer input into quantifiable design concerns –Physical - lightweight –Structural - adequate strength –Environmental - will not degrade when exposed to water –Human engineering - accessibility to controls –Life cycle - easy to service –Cost - affordable price

DETERMINING ASSESSMENT MEASURES FOR EACH DESIGN CONCERN Definition: what will be measured to determine how the design performs with respect to the specific design concern (note units) Definition: what will be measured to determine how the design performs with respect to the specific design concern (note units) Requirement: if the design concern is a requirement, what is the level (value) of the assessment measure which has to be achieved in order to comply with the requirement (for a design concept to be considered a possible solution) Requirement: if the design concern is a requirement, what is the level (value) of the assessment measure which has to be achieved in order to comply with the requirement (for a design concept to be considered a possible solution) Goal: if the design concern is a goal, what is the desired direction of the assessment measure in order to come closer to achieving the goal (the design concept which performs most favorably with respect to the goals is the best solution) Goal: if the design concern is a goal, what is the desired direction of the assessment measure in order to come closer to achieving the goal (the design concept which performs most favorably with respect to the goals is the best solution) For the bicycle example For the bicycle example