C1.0 Design Specifications.pptx
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Transcript C1.0 Design Specifications.pptx
Defining Design Goals and
Design Requirements
Engineering Design and Development
© 2013 Project Lead The Way, Inc.
As we review current and past solution attempts to
the problem we have identified;
it is important to begin analyzing what the critical
design goals and requirements will be in any
solution attempted.
An Engineering Design Process - Research
1. Define and Justify a Problem
• Brainstorm possible project problems.
• Research and select a valid problem.
• Become an expert on the problem.
• Justify the problem through research.
• Academic
• Market
• Write a problem statement.
• Document and analyze prior solutions.
• Identify design requirements.
• Create a Project Proposal or
Business Plan
Design Goals and Design Requirements
What are Design Goals and Design Requirements?
• Fundamental Design Criteria – Addressed in almost all
design.
• Specifications – What does it do?
– Design Specification: Precise and explicit information about the
requirements for a successful solution to a problem
– Product (Technical) Specification: Explicit set of requirements that
must be met in order for a product to operate as designed
• Features – What do end users want?
• Constraints – What are your limiting factors in the design?
• Parameter – What are the testable features in your design?
Design Goals and Design Requirements
What are Design Goals and Design Requirements?
Specifications - plural of spec·i·fi·ca·tion (Noun)
1. An act of describing or identifying something precisely or of
stating a precise requirement.
2. A detailed description of the design and materials used to
make something.
Constraints - plural of con·straint (Noun)
1. A limitation or restriction.
Parameter- plural of pa·ram·e·ter (Noun)
1. A numerical or other measurable factor forming one of a set
that defines a system or sets the conditions of its operation.
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.
Eight Fundamental Design Criteria
Design Criteria
1. Form
– Product Size and Shape
2. Function
– Performance
– Durability
– Maintenance
– Standardization
3. Materials
– Life Cycle of the Product
– Environmental Impact
4. Aesthetics
5. Ergonomics
6. Safety and Legal Issues
7. Cost
8. Customer Needs
Eight Fundamental Design Criteria
FORM
• Size and Shape
• Dimensions
• Weight
Eight Fundamental Design Criteria
FUNCTION
What does it need to do? How will it work?
• Performance
• Durability
• Maintained
• Standardization.
©iStockphoto.com
Eight Fundamental Design Criteria
FUNCTION
• Specify the function of the product
– What will the product need to do?
©iStockphoto.com
• 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?
Function:
DURABILITY
Eight Fundamental Design Criteria
Operating Environment
– Product will encounter a wide range
of environments from manufacture to
operation by the customer
•
•
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Temperature range
Corrosive environments
Dust or dirt
Pressure and humidity
Vibration and noise
Degree of abuse
Eight Fundamental Design Criteria
Function:
STANARDIZATION
•
•
•
•
Specifications – What does it do?
Features – What do end users want?
Constraints – What are your limiting factors in the design?
Parameter – What are the testable features in your design?
Eight Fundamental Design Criteria
MATERIALS
Often chosen by the design team to meet criteria, but
sometimes dictated based on special needs or availability.
• Durability
• Life Cycle of the Product
• Environmental Impact
©iStockphoto.com
Eight Fundamental Design Criteria
Materials:
LIFE CYCLE OF PROCUCT
• 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: making products in such a way
that they become out-of-date or useless within a known
period.
©iStockphoto.com
Eight Fundamental Design Criteria
Materials:
ENVIROMENTAL IMPACT
What affect will the product have on
the Earth’s environment?
How will the product be disposed of?
©iStockphoto.com
Eight Fundamental Design Criteria
AESTHETICS
• The way that a product looks will affect marketability,
especially for a consumer item.
– Color
– Surface Treatment
– Shape
– Material
• Integrating visual appeal with functionality is one
key to the consumer’s heart.
Eight Fundamental Design Criteria
ERGONIMICS
• Ergonomics is the science of how
humans interact with objects in their
environment.
• Products should be designed for
human comfort, efficiency, safety,
and ease of use
• Create products that “fit” the user so
that the product is comfortable,
efficient, safe, and easy to use.
Eight Fundamental Design Criteria
SAFETY AND LEGAL ISSUES
• Human health and safety
• Product liability laws expose manufacturers to lawsuits if
their products fail
Eight Fundamental Design Criteria
COST
• Cost will impact you dramatically.
• Most of your project will be done with little to no budget.
Specifications
An act of describing or identifying something
precisely or of stating a precise requirement.
A detailed description of the design and materials
used to make something.
Design Specification
• Specific, concise written information about the
requirements that must be met in order to attain the
intended outcome
• Design Specifications include:
– Criteria
– Constraints
• Must be specific and unambiguous
• Client must be involved
Constraints
A limitation or restriction.
Constraints
The limits on the design and production of a
product
–
–
–
–
–
–
–
Resources (people, equipment, etc.)
Budget
Time
Energy
Materials
Manufacturing Process
Others
Parameters
A numerical or other measurable factor forming
one of a set that defines a system or sets the
conditions of its operation.
Parameters
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