Chapter 1


Chapter 1

The Product Design Process

The Four C’s of Design

A Simplified Approach

A Problem Solving Methodology

Consideration of A Good Design

The Four C’s of Design


• Requires creation of something that has not existed before or not existed in the designer’s mind before


• Requires decisions on many variables and parameters


• Requires making choices between many possible solutions at all levels, from basic concepts to smallest detail of shapes


• Requires balancing multiple and sometimes conflicting requirements

What is Design?

Design establishes and defines solutions to and pertinent structures for problems not solved before, or new solutions to problems which have previously been solved in a different way

• Difference between Design and Discovery:

Discovery is getting the first sight of something but design is the product of planning and work

• Good design requires both analysis and synthesis

(Analysis is to breakdown complex problems to manageable parts and synthesis involves the identification of the design elements that will compromise the product and the combination of the part solutions into a total workable system)

The Design Process- A

Simplified Approach

General information

Specific information

Design Operation Outcome

Feedback loop

NO yes


Go to the next step

Scientific Method vs Design Method

Existing knowledge

Scientific curiosity


Logical analysis


Scientific Method

State of the art

Identification of need


Feasibility analysis


Design Method

Consideration of Good Design

Design Requirements

– Functional performance (F, σ, power, deflection)

Complementary performance (life of design, robustness, reliability, ease, economy, safety of maintenance)

Total Life Cycle

Material selection, productivity, durability

Regulatory and Social Issues

ASTM, ASME standards, codes of ethics, EPA requirements

Design Process

• I. Conceptual Design

• II. Embodiment Design

• III. Detail Design

• IV. Planning for Manufacture

• V. Planning for Distribution

• VI. Planning for use

• VII. Planning for Retirement of the Product

I. Conceptual Design

• Identification of customer needs

• Problem definition

• Gathering information

• Conceptualization

• Concept selection

• Refinement of product design specification

• Design review

II. Embodiment Design

• Product architecture

• Configuration design of parts and components

(feature present like holes, ribs, splines, and curves are configured). Modeling and simulation may be performed. The generation of physical model of the part with rapid prototyping processes may be appropriate)

• Parametric design of parts and components

(exact dimensions and tolerances, materials and processes, robustness)

III. Detail Design

• In this phase the design is brought to the stage of a complete engineering description of a tested and producible product.

IV. Planning for Manufacture

• Designing specialized tools and fixtures

• Specifying the production plant that will be used

• Planning the work schedules and inventory controls

• Planning the quality assurance systems

• Establishing the standard time and labor costs for each operation

• Establishing the system of information flow necessary to control the manufacturing operation

V. Planning for Distribution

• Shelf life consideration

• System of warehouses for distribution of the product needs to be designed

• Marketing efforts on advertising and news media techniques must be selected

• For technical activities specialized sale brochures and performance test data must be generated.

VI. Planning for use

• Ease of maintenance, reliability, product safety, convenience in use (human factors engineering), aesthetic appeal, economy of operation, and duration of service are some of the questions to be answered in a consumer oriented product.

• Acquisition of reliable data on failure, service lives, and consumer complaint and attitudes to provide a basis for product improvement in the next design is an important phase VI activity.

VII. Planning for Retirement of the Product

• The final step in the design process is the disposal of the product when it has reached the end of its useful life.

• Useful life may be determined by actual deterioration and wear or it may be determined by technological obsolescence.

• Industrial ecology considerations dictate a plan for either disposal of the product in an environmentally safe way or, better, the recycling of its materials, or remanufacture or reuse of product components.