Design Criteria and Constraints Presentation Name Course Name Unit # – Lesson #.# – Lesson Name Design Criteria and Constraints Design is directed toward human beings. To design is to solve human problems by identifying them and executing the best solution. Ivan Chermayeff Introduction to Engineering Design © 2012 Project Lead The Way, Inc.

Design Criteria and Constraints Performance Product Size and Shape Aesthetics Materials Safety and legal Issues Ergonomics Environment Life Cycle Durability and Maintenance Design Constraints Measurable Values

Example Design Specification Presentation Name Engineering Design and Development Unit # – Lesson #.# – Lesson Name Example Design Specification Design a pet restraint system to keep a dog safe.

Criteria and Constraints Presentation Name Engineering Design and Development Unit # – Lesson #.# – Lesson Name Criteria and Constraints Specific, concise written information about the requirements that must be met in order to attain the intended outcome Must be specific and unambiguous Client must be involved

Presentation Name Engineering Design and Development Unit # – Lesson #.# – Lesson Name Design Criteria The explicit requirements that a product must meet in order to be successful Used to evaluate a product’s potential to be successful Used to create testing procedures May address Performance Maintenance Product Size and Shape Customer Needs Aesthetics Others Materials Safety and Legal Issues Ergonomics Environment Life Cycle

Performance Specify the function of the product Presentation Name Engineering Design and Development Unit # – Lesson #.# – Lesson Name Performance Specify the function of the product What will the product need to do? Example: When designing a special fork lift for a warehouse, How will the vehicle be powered? What is the maximum speed? On what surfaces must the vehicle operate? What turning radius is required? What are the dimensions of the cargo to be lifted? What is the maximum load to be lifted? How high must the cargo be lifted and stored? ©iStockphoto.com

Product Size and Shape Form Dimensions Weight Presentation Name Engineering Design and Development Unit # – Lesson #.# – Lesson Name Product Size and Shape Form Dimensions Weight

Presentation Name Engineering Design and Development Unit # – Lesson #.# – Lesson Name Aesthetics The way that a product looks will affect marketability, especially for a consumer item. Color Surface Treatment Shape Material

Presentation Name Engineering Design and Development Unit # – Lesson #.# – Lesson Name Materials Often chosen by the design team to meet criteria, but sometimes dictated based on special needs or availability ©iStockphoto.com

Safety and Legal Issues Presentation Name Engineering Design and Development Unit # – Lesson #.# – Lesson Name Safety and Legal Issues Human health and safety Product liability laws expose manufacturers to lawsuits if their products fail ©iStockphoto.com ©iStockphoto.com

Ergonomics The science of designing according to human needs Presentation Name Engineering Design and Development Unit # – Lesson #.# – Lesson Name Ergonomics The science of designing according to human needs Products should be designed for human comfort, efficiency, safety, and ease of use

Environment Operating Environment Presentation Name Engineering Design and Development Unit # – Lesson #.# – Lesson Name Environment Operating Environment Product will encounter a wide range of environments from manufacture to operation by the customer Temperature range Corrosive environments Dust or dirt Pressure and humidity Vibration and noise Degree of abuse

Environment Global Environment Presentation Name Engineering Design and Development Unit # – Lesson #.# – Lesson Name Environment Global Environment What affect will the product have on the Earth’s environment? How will the product be disposed of?

Presentation Name Engineering Design and Development Unit # – Lesson #.# – Lesson Name Life Cycle Service Life: The length of time a product is expected to operate properly without need for repair Product Life: The length of time a product will undergo production before being replaced with a newer version Planned Obsolescence: A manufacturing decision by a company to make consumer products in such a way that they become out-of-date or useless within a known period.

Durability and Maintenance Presentation Name Engineering Design and Development Unit # – Lesson #.# – Lesson Name Durability and Maintenance Product should not need major repairs within the service life Routine maintenance should be planned Routine maintenance should be easy Plan for access Necessary tools Replacement parts

Presentation Name Engineering Design and Development Unit # – Lesson #.# – Lesson Name Design Constraints The limits on the design and production of a product Resources (people, equipment, etc.) Budget Time Energy Materials Manufacturing Process Others

Presentation Name Course Name Unit # – Lesson #.# – Lesson Name Measurable Values Each criteria and constraint should be expressed with specific or measurable value(s). Evaluation of Conceptual Designs Testing Criteria

Measurable Values Poor Specification: The device must warn the driver and slow the vehicle when the car is too close to an object. Better: Within one second the device must warn the vehicle driver and disengage the cruise control when the car attains a distance of less than 50 ft directly between itself and another vehicle.

Image Resources Microsoft, Inc. (n.d.). Clip art. Retrieved from http://office.microsoft.com/en-us/clipart/default.aspx iStockphoto. Retrieved from www.istockphoto.com