1 Chapter Seven Engineering Design. 2 Introduction Design: is the process of turning ideas into physical reality. Design used to create new product.

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Chapter Seven

Engineering Design

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Introduction

Design: is the process of turning ideas into physical reality.

Design used to create new product and to build new devices and systems that meet a human need.

The new design might be a radical departure from anything that already exists, or an incremental improvement to an existing design.

Engineering design = = Creative process.

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Design Versus Analysis

Analytical problems:1. Called “word Problems”, “Story

Problems”, or “Closed-Ended Problems”.2. There is only one correct answer. Design problems:1. Called “Open-Ended Problems”2. There is no unique correct answer.3. Each solution has its good and bad points.

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The Engineering Design Process

A nine-step design sequence is introduced it is applicable for both hardware and software design.

This process is not linear moving directly from a start point to an end point.

The engineer may go back to a previous step as the design proceeds.

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1. Decide on needs. Having an idea for the new device or product,

to decide on the need of the customer The idea can come from the customer, or and

engineer who has who sees the need for a new product.

This step requires a great deal of thinking or research to determine whether the idea is feasible, new, and can be sold.

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2. Develop product specifications. In this step detailed thinking is done to decide

how the device should perform, its cost, how it will look like, and when it will be finished.

Specifications and the changes are often decided on in consultation with the customer.

Specifications are moving targets, that is you may end with something different than what you started with

Specifications may be altered or tightened to be competitive in the marketplace.

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3. Develop a project plan. The project plan is the basic road map used by

engineers to efficiently complete a project. Planning takes a great deal of time. Careful planning makes the design process run

more smoothly and efficiently. Engineers need to plan how to attack a

problem in order to ensure that it will be successfully completed in the least amount of time.

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4. Develop a block design. The design is performed at a functional

level rather than at detailed level. The functional block and their interactions are mapped out.

Engineers develop several ideas simultaneously and do not limit themselves to one design concept.

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4. Develop a block design (Cont.): Developing more than one design has many

advantages: An idea from one design will be applicable in

another one. Ways to combine two design together to form

a better design may become apparent as work on several alternatives.

If one design does not turn out to be feasible, the backup design will be ready saving a great deal of time.

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5. Generate detailed design of each block.

Perform detailed designs of each of the blocks mapped out in the previous step.

The design is at the component level, with individual transistors, integrated circuits, or lines of software being selected.

Generate alternatives as well.

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6. Select the best alternative. After generating the design, select the

most promising design among the alternatives.

The choice for the alternative should be based on detailed calculations and analysis, including simulation

A prototype of the design is built and extensively tested.

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7. Test and verify the design Testing is quite extensive and may

include basic test to see if the design functions as planned and meets the specifications.

Test are made to see how long the design lasts, and how it performs in extreme conditions.

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8. Manufacture. Work with manufacturing engineers to

ensure that the device is fabricated properly and works as planned after manufacturing process, design may be modified to make it simpler, or less expensive

9. Deliver the finished product or device to the customers.

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Team Work

Most of engineering design projects are performed by teams of engineers working together.

Every member of a team brings a different set of skills (different technical abilities or knowledge) to a project, and different interaction styles and approaches to work with others.

Teams without diversity generally do not function very well

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Team Work Some interaction styles:a) Some are very good on detailed technical

tasks.b) Some have a good leadership skills.c) Some are better at working on a piece of

the project individually.d) Some are good at communicating ideas.e) Some are better at challenging the

thinking of other team members.

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Team Work Every team needs people who are highly

competent, and task oriented, and who strive high quality.

Teams also need people who are flexible. All teams need good communicators to ensure

that oral and written reports convey the proper information about the project.

These qualities will not all appear in only one individual so the team will include a blend of all personality types.

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Team Work The characteristics of effective teams include:1. Having a good leadership and clear purpose.2. They work informally and have open discussions

with an agreement that any disagreement will be civilized and not personal

3. Everyone participates and everyone listens to other team members.

4. There are very clear roles and work assignments for every team member.

5. Effective teams have a blending of different personal styles.

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Concurrent Engineering

In most corporations the engineering design process is performed using a method called concurrent engineering

In the Old models of the design process various tasks were handled sequentially.

Engineers were grouped according to specialties (academic disciplines), called departments in large companies.

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Concurrent Engineering

The successful completion of the projects require interaction between engineers of different departments, this was done at meetings.

This process allowed engineers to specialize and become very good at their area. They could easily help each other out.

The disadvantage was that the time required to complete the design was very long.

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Concurrent Engineering In concurrent engineering design is

performed by multidisciplinary teams, all engineers will work together from the beginning.

Design teams often include marketing experts or purchasing specialists and sometimes customers.

This system has been able to reduce the time required to bring a new product to market through addressing issues early in the design cycle.

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Other Design Considerations1. Safety All products meet minimum standards of safety. The IEEE code of ethics states that an engineer

is responsible for ensuring the safety of those who will use his or her design.

There are many legal requirements and safety standards that an engineer is required to follow, these provide a good foundation for producing safe designs

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Other Design Considerations When a design is in a new area engineers

must recognize that nothing is 100% safe, there are ways that any product can be misused, and there are unanticipated in a design it is the engineer’s job is to try to anticipate and prevent these things.

Safety can be ensured at the basic steps of the design, that is when the different alternatives are being considered, safety should be given equal weight as all other design considerations.

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Other Design Considerations

2. Environment IEEE code of ethics requires engineers to

produce their design in accordance with sound environmental principles.

The generation of hazardous wastes during the production process is minimized.

When a product expires there are ways to recycle it or to minimize its negative impact on the environment during disposal.

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3. Design for Testability The specifications for a product often spell out

the test procedure that will be used to verify that the product works as it is supposed to.

The design engineer should ensure that the testing can be performed easily

Placing easily accessible test areas on the design makes it easy to troubleshoot the design or even fix it later.

Incorporating testability in the original design makes the whole design process more efficient.

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4. Design for Manufacturability It is essential to incorporate manufacturability

into design from the start. Anything that is complicated to assemble

requires specialized and expensive workers, adding cost to the overall design.

Design engineers must work closely with the manufacturing specialists to incorporate manufacturability into the design, this is done at the stage of considering the alternatives.

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5. Esthetics Performing designs that are pleasing to

eye gives more satisfaction. Laying out components in a pleasing

manner or helping to design a unique looking case for a new product.

Esthetics are not included in the specifications but it is necessary to include it as a criteria.

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Engineering Communication

Engineers who wish to proceed with their profession must have high-quality communication skills. Types of engineering communications include:

1. Engineering Logbooks Also called Lab books, are a means for recording all

the work done on a project in a single place. Engineers use logbooks to record all calculations

that were made, detail all of the design work, record test data, record information about meetings and contacts with suppliers or customers.

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The engineer is the only one who will see the logbook, although some companies insist on keeping logbooks when an engineer leaves the company.

Advantages of Logbook:1. Easier to find information about the project later

on, when details are hard to remember.2. Better to keep data in a book than on individual

sheets of paper that can be lost or destroyed.3. Satisfy the legal requirement for defending a

patent, in a dispute about who came up with an idea first, complete logbooks will aid in establishing whose work came first

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2. Memos: Memos tend to be short. Memos are used for a variety of purposes

including setting up meetings, soliciting information from other engineers or suppliers, briefly communicating the status of a project.

It might be written to your manager or members of your organization.

Memos are written by individual engineers.

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3. Progress Reports Engineers provide periodic progress reports to a customer

or the manager. These reports detail what has happened during the

reporting period and what work is planned for the next period.

This type of reports provide good channels of communication between the engineer and his customer or the management.

It allows for timely reporting of any problems that may come up.

Periodic reports may be weekly, monthly, yearly or any convenient period.

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4. Feasibility Studies It is much longer than memos and progress

reports It is done early in a project. Requires a lot of background work and

preliminary design to answer some important questions about:

a) Whether the contemplated project can be doneb) Whether it makes economic sense to pursue it.c) Whether it can be done in reasonable time.

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5. Proposals A detailed document laying out the plans and

costs to complete a project. They go out to potential customers or to

higher levels of management within the company to obtain permission and resources to start a new project.

Engineers works with technical writers to produce high-quality proposals to present the idea effectively in order to compete with other proposals.

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6. The Engineering Design Report This is a detailed report on how the design

was done and how well it worked, it is submitted after the completion of the project.

It may be submitted to the customer who paid to the design or for the management

It contains information on the problem being addressed and the background information that was used in working on the design.

It also contains information about how the design was performed, how it was tested, and the results obtained.

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It may include recommendations for improvements to the design, which also makes it valuable to the customer.

It is important for the engineers who might do similar projects in the future to help prevent “reinventing the wheel”.

In large companies technical writing experts are responsible for writing these reports with the help of the engineers who worked on the project.

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7. Technical Manual It is called owner’s manual. It focuses on how to operate and maintain

the device, while the design report focuses on how the device was designed.

It shows the customer how to use the device properly, and how and when to perform periodic maintenance, and how to perform simple troubleshooting and repair.

It is prepared by technical writers with significant input from the engineers.

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8. Engineering Drawings The best way to convey engineering information is

through a drawing. Schematic diagram: is a symbolic representation of

electrical components and the way they are interconnected, and what types of voltages and waveforms should appear at various places in the circuit.

It allows the designer to visualize his thoughts about the design.

It also allows engineers to understand a circuit and technicians to properly build it.

It is indispensable in repairing a circuit that is not working correctly.

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9. Oral Presentations It can be done at a department meeting,

as a talk at a meeting of an engineering professional society, or to a potential customer, or higher management.

Oral reports are fairly formal. It is important for an engineer to be able

to communicate effectively orally as well as in writing.

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Creativity

Bringing a design from a concept to finished product requires new solutions and new ideas.

Some people are highly creative by nature, but everyone can learn methods to help enhance their creativity.

According to the split-brain theory the human brain is divided into two halves, called the left side and the right side.

The various human activities are housed on different sides of the brain.

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Creativity For example in right-handed people the left

hemisphere tends to concentrate verbal and symbolic logical reasoning, the right hemisphere concentrates the spatial and holistic reasoning processes. The opposite is true for left-handed people.

Educational processes are dominated by left-brain learning, however engineering design requires right-brain processes especially holistic analysis and synthesis.

Attributes of the left side are precision, logic, linearity, and order. The right side is experimental, imaginative, creative and risk taking.

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Creativity

Some things that can stifle creativity:1. Habits: Often, we are so set in our ways that we don’t

entertain any creative or new thoughts for very long.2. Fear of failure: sometimes we are scared we will fail or

our ideas will not work, that we suppress new ideas.3. Culture blocks: culture of our organization does not

value creativity.4. Narrow-mindedness: many people think narrowly, and

cannot look at things in new ways.5. Negativity: Colleagues who feel threatened by new

ideas or who are not themselves capable of creative thinking, will stifle your new good ideas.

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Creativity Steps to opening up creativity include1. Recognize the stiflers of creativity, once you understand

their nature you can overcome or work around them.2. Spend some eating & writing with your nondominant

hand, this will stimulate the underused half of your brain.3. Engage in “information gathering” to get new ideas and

to broaden your thinking.4. In teams a process called brainstorming is used, where a

team meets for coming up with new ideas. During this process new ideas are not to be criticized as a bad idea may stimulate a good one from another team member. Once the ideas are all laid out the evaluation period begins.

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Intellectual property

Intellectual property: is information that gives company a competitive advantage over other companies in some business.

Intellectual property forms:1. Information about new designs and

processes.2. Financial practices of the company.3. Information about corporation’s

customers and suppliers.

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Intellectual propertyLegal means to protect intellectual property:1. Keep trade secrets within the company. When hired

by a company employees sign an agreement that guarantees they will not divulge trade secrets to anyone outside the company.

2. Patent is a grant by the government that gives the inventor the right to exclude others from making, using or selling the invention for a given period of time.

Patents are public information so competitors can invent their own variations. Patents are granted to a person who later assigns his patents to companies.

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Intellectual property There are two types of patent:a) Design patent: covers only the appearance of an

invention not its structure and utility.b) Utility patent: covers mechanical, chemical, or

electrical inventions and can include devices, products, and processes.

Utility patents can be issued for:a) New and useful processes, machines,

manufactures, compositions of matter, or biotechnology.

b) New and useful improvements on things that have already been patented.

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What cannot be patented?a) Devices that have already been invented

by someone else even if they did not obtain the patent.

b) Devices already for sale or described in publication more than one year prior to the filing date of the patent.

c) Methods of doing business, the basic laws of science.

Computer software can now be patented.

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3. Copyrights: exclude others from copying or using your creative works these include (books, works of arts, music, photographs, and notes). This often covers computer software.

4. Trade mark: is mark, word, or symbol that is applied to commercial goods.

Trade marks are unique symbols or product names that a company wishes to retain for its own exclusive use. (10 years and can be renewed)

1 Chapter Seven Engineering Design. 2 Introduction Design: is the process of turning ideas into physical reality. Design used to create new product.

Documents

design problems

new design

block design

engineering design process

engineering design slide

introduction design

better design

existing design