COURSE OF ME 362 MECHANICAL ENGINEERING
DESIGN Part 3.2
M M Jan
TODAYS TOPICS
Design Review
Re-Design
Technology innovation
Product life cycle
DESIGN REVIEW
It is a vital aspect of Design Process in which specialists review the design
Provides an opportunity for specialists from different disciplines to interact with generalists to ask critical questions and exchange vital information
Provides a systematic method for identifying Problems with the design Aids in determining possible
courses of action Initiates action to correct the
problem areas
DESIGN REVIEW
Design review teams consist of representatives from Design, manufacturing, marketing, purchasing, quality
control, reliability engineering and field service
Design Reviewer should Have broad technical and products knowledge Have not direct responsibility for design under review Depending on the size and complexity of the product,
Design Review should be held from 3~6 times in the life of the project
DESIGN REVIEW Minimum review schedule consists of
Conceptual Reviews It has a greater impact on design Changes can be made at this stage at lower costs
Interim Reviews This is performed when embodiment design is
finalized, product architecture, subsystems and performance characteristics are established
Final Reviews At the completion of detailed design and establishes
whether the design is ready for transfer to manufacture Outcome of review
Each review of the product design may have two outcomes Technical aspect Business aspect
DESIGN REVIEW TECHNICAL ASPECT Product Design Specification (PDS) PDS is the basic reference document for both product
design and design review
Essence of Technical Review of design is to compare the finding against detailed PDS formulated at the product definition stage of the project
PDS is a detailed document that describes what the design must be in terms of performance requirements, environment in which it must operate, product life, cost, reliability and a number of other design requirements
RE-DESIGN
A common situation in Design Process
The task may be to improve an existing design.
Or it may be due to reason that a component in a product is
failing in service
Sometimes, we redesign a component so as to reduce its
cost of manufacture. e.g., the
change in the shape of a part to
reduce a stress concentration
Sometimes, a new material is substituted to reduce weight or
cost
En
gin
eeri
ng d
esi
gn
Original design
Adaptive design
Redesign
Selective design
Industrial design
RE-DESIGN
As a result of Design Review, Details of design are changed many times as prototypes are
developed and tested
Categories of Re-design
Fixes
Updates
RE-DESIGN CATEGORIES o Fixes
A fix is a design modification that is required due to less than acceptable performance (after the product has been introduced into the market) unplanned activity!
o Updates Usually planned as part of the products life cycle before the
product is introduced to the market An update may add capacity and improve performance or
incorporate its appearance to keep it competitive The most common situation in re-design is the modification
of an existing product to meet new requirements e.g. banning of the use of fluorinated hydrocarbon refrigerants because of Ozone-hole problem, required the extensive re-design of refrigeration system
Often re-design results from the failure of the product in service
RE-DESIGN
Case study of redesign of a railroad vehicle wheel
The steel railroad wheel has been in its present design for nearly 150 years
In spite of improvements in metallurgy and the understanding of stresses, the wheels
still failed at the rate of about 200 per year
The chief cause of failure is thermal buildup caused by failure of a railcars braking system
Long-term research by the Association of American Railroads has resulted in the
improved design
RE-DESIGN
Old Vs. New design The chief design change is that the flat plate,
the web between the bore and the rim, has
been replaced by an S-shaped plate
RE-DESIGN
Case study of redesign of a railroad vehicle wheel
The advantage of the curved shape is that it allows the plate to act like a spring, flexing
when overheated, avoiding the buildup of
stresses that are transmitted through the
rigid flat plates
The second change in the design of the wheel is the wheels tread it has been redesigned to extend the rolling life of the
wheel
The new wheels last for many thousands of
miles longer, and the rolling resistance is lower,
saving on fuel cost
RE-DESIGN
Case study: GM Ignition Switch GM: 1908 US Head office: Detroit A leading car manufacturer Products
Alpheon, Chevrolet, Buick, GMC, Cadillac, Holden, HSV, Opel, Vauxhall,
Wuling, Baojun, Jie Fang, UzDaewoo
Worldwide collaborations Pakistan: Ghandhara Industries
RE-DESIGN
Case study: GM ignition switch GM began developing new small cars
in the late 1990s
Chevrolet Cobalt Saturn Ion
In an effort to improve its new cars they listened to customers who complained about cheap-feeling switches that required too much
effort to turn
The new design of the switch was such that it was working more
smoothly and gave drivers the
impression that they were better
designed
RE-DESIGN
Example: GM ignition switch the other side of the story:
The ignition switch consists of Mechanical Electronics
GM made the mechanical alteration in the spring of the ignition switch
Anyhow, GM engineer approved the new design The result was a smooth-turning key However, it was so smooth that it
could also slip out of position
RE-DESIGN
The slipping of the key to other position occurred in many cars That caused the engine to stop during running of the car The stopped engine deactivated the air bag!
More than 50 car crashes 13 deaths More than 100 injuries The company has to
recall about 2.5 million
cars (until 2014) All 2005-2010 Chevrolet Cobalt 2007-2010 Pontiac G5 2003-2007 Saturn Ion 2006-2011 Chevrolet HHR 2006-2010 Pontiac Solstice 2007-2010 Saturn Sky
[Ref. Automotive news]
RE-DESIGN
Example: GM ignition switch the other side of the story:
What is the difference between these
pictures?
RE-DESIGN
TECHNOLOGY INNOVATION AND DESIGN PROCESS
Technology innovation is the process through which new (or improved) technologies are
developed and brought into widespread use
A successful technological innovation requires a good idea or concept that satisfies a societal need
Advancement of technology has three phases: Invention Innovation Diffusion
TECHNOLOGY INNOVATION AND DESIGN PROCESS
Invention: Creative act whereby an idea is conceived, articulated and recorded
Innovation: Process by which an invention or idea is brought into successful practice and is utilized by the economy
Diffusion: The continual and widespread implementation and adoption of successful innovation
Innovation is the most critical and most difficult of three phases
STEPS IN A TECHNOLOGICAL INNOVATION ACTIVITY
Identification of market
need
Product idea
Development Pilot lot Trial Sales
Commercial development
Innovation is the most critical and most difficult of three phases
Because, developing an idea into a product that people will buy requires hard work and skill. Technology innovation activity consist of different stages:
sometimes, Market need is stronger than technological research opportunity
Product ideas must be checked for their fit with the ongoing technology
Time and management about 35 to 50% of new products fails due to above
Generally, the technical problems comprise the smallest category of failure during the development
KEY FACTORS FOR THE SUCCESS OF THE PRODUCT
1. Product planning and research: It is important that adequate time spent on problem definition,
concept generation and evaluation, market research and assessment, technical assessment, business and financial reviews before embodiment and detail design stages
2. Product superiority: Product should be such that it delivers real value to customer
i.e. meeting customer needs (example: energy savor lights) 3. Quality marketing:
Better marketing activities to be executed from concept of idea to launch of product in market.
4. Proper organizational design: Successful products are most often developed by cross
functional teams, led by strong product champion, supported by top management and accountable (responsible!) for the entire project from beginning to end.
KEY FACTORS FOR THE SUCCESS OF THE PRODUCT
Which qualities are expected from Innovators?
FIVE KINDS OF PEOPLE NEEDED FOR
TECHNOLOGICAL INNOVATION
1. Idea generator: The creative individual 2. Entrepreneur: (organize & manage)The person who carries the ball
and takes the risks 3. Gatekeepers: People who provide technical communication from
outside to inside the organization 4. Program manager: The person who manages without hindrances 5. Sponsor: The person who provides financial and moral support, often
senior management
Roughly 70 to 80% of people in technical organizations are routine problem solvers and are not involved in innovation. Therefore it is
important to identify and nurture the small number who gives promise of becoming technical innovators
INNOVATORS
People in a technical organization, who are most current with technology and who have developed contacts with technical people outside the organization
Receive information directly and diffuse to others in organization Tend to be predisposed to do things differently as contrasted with
doing things better Able to deal with unclear and ambiguous situations without feeling
uncomfortable as they have high degree of self-reliance and self-esteem Respond well to the challenge of diverse projects and the opportunity to
communicate with people of different backgrounds A successful innovator is a person who has sound picture of what needs
to be done, not necessarily a detailed picture Emphasis goals, not methods of achieving goals Have been failed in previous ventures and knows why and how to get
them? Works the element of problem in parallel not serially
PRODUCT LIFE CYCLE
o During the lifetime of a product, each product goes through a cycle
o This life cycle consists of Birth stage Initial growth stage Stable period Declining state
PRODUCT LIFE CYCLE
Birth Stage Initial Growth Stage
Introductory stage: Product is new, consumer acceptance is low, so sales are low, rate of product change is rapid as management tries to maximize its performance or uniqueness
Growth Stage: Knowledge of the product and its capabilities reaches to growing number of customers. In this stage there is an increase in sales as the time passes
PRODUCT LIFE CYCLE
Birth Stage Initial Growth Stage Mature stage Decline stage
Maturity Stage: Product is widely accepted, sales are stable, grow at the same rate. Products at this stage experience considerable competition Great emphasis is on reducing the cost of a mature product
When product reaches at this stage, attempts should be made to renew it by incremental innovation or development of still new applications
Decline Stage: At some stage each product enters in this stage Sales decrease because a new better product is in the market to fulfill the same societal
needs
PRODUCT LIFE CYCLE If we look more closely at the product life cycle, we will see that the cycle is made up of many individual processes These are Premarket phase and Market phase processes
Premarket Phase
1. Idea generation 2. Idea evaluation 3. Feasibility analysis 4. Technical R&D 5. Product (market) R&D 6. Preliminary production 7. Market testing 8. Commercial production
Market Phase
9. Product introduction 10. Market development 11. Rapid growth 12. Competitive market 13. Maturity 14. Decline 15. Abandonment
Premarket Phase 1. Idea generation 2. Idea evaluation 3. Feasibility analysis 4. Technical R&D 5. Product (market) R&D 6. Preliminary production 7. Market testing 8. Commercial production
PRODUCT LIFE
CYCLE
inve
stm
ents
sale
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Market Phase 9. Product introduction 10. Market development 11. Rapid growth 12. Competitive market 13. Maturity 14. Decline 15. Abandonment
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